1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0 2daa93fabSSam Ravnborg# Select 32 or 64 bit 3daa93fabSSam Ravnborgconfig 64BIT 4104daea1SMasahiro Yamada bool "64-bit kernel" if "$(ARCH)" = "x86" 5104daea1SMasahiro Yamada default "$(ARCH)" != "i386" 6a7f7f624SMasahiro Yamada help 7daa93fabSSam Ravnborg Say yes to build a 64-bit kernel - formerly known as x86_64 8daa93fabSSam Ravnborg Say no to build a 32-bit kernel - formerly known as i386 9daa93fabSSam Ravnborg 10daa93fabSSam Ravnborgconfig X86_32 113120e25eSJan Beulich def_bool y 123120e25eSJan Beulich depends on !64BIT 13341c787eSIngo Molnar # Options that are inherently 32-bit kernel only: 14341c787eSIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION 15341c787eSIngo Molnar select CLKSRC_I8253 16341c787eSIngo Molnar select CLONE_BACKWARDS 17157e118bSThomas Gleixner select GENERIC_VDSO_32 18117ed454SThomas Gleixner select HAVE_DEBUG_STACKOVERFLOW 19157e118bSThomas Gleixner select KMAP_LOCAL 20341c787eSIngo Molnar select MODULES_USE_ELF_REL 21341c787eSIngo Molnar select OLD_SIGACTION 222ca408d9SBrian Gerst select ARCH_SPLIT_ARG64 23daa93fabSSam Ravnborg 24daa93fabSSam Ravnborgconfig X86_64 253120e25eSJan Beulich def_bool y 263120e25eSJan Beulich depends on 64BIT 27d94e0685SIngo Molnar # Options that are inherently 64-bit kernel only: 284eb0716eSAlexandre Ghiti select ARCH_HAS_GIGANTIC_PAGE 29c12d3362SArd Biesheuvel select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 30d94e0685SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF 31d94e0685SIngo Molnar select HAVE_ARCH_SOFT_DIRTY 32d94e0685SIngo Molnar select MODULES_USE_ELF_RELA 33f616ab59SChristoph Hellwig select NEED_DMA_MAP_STATE 3409230cbcSChristoph Hellwig select SWIOTLB 357facdc42SAl Viro select ARCH_HAS_ELFCORE_COMPAT 3663703f37SKefeng Wang select ZONE_DMA32 371032c0baSSam Ravnborg 38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE 39518049d9SSteven Rostedt (VMware) def_bool y 40518049d9SSteven Rostedt (VMware) depends on X86_32 41518049d9SSteven Rostedt (VMware) depends on FUNCTION_TRACER 42518049d9SSteven Rostedt (VMware) select DYNAMIC_FTRACE 43518049d9SSteven Rostedt (VMware) help 44518049d9SSteven Rostedt (VMware) We keep the static function tracing (!DYNAMIC_FTRACE) around 45518049d9SSteven Rostedt (VMware) in order to test the non static function tracing in the 46518049d9SSteven Rostedt (VMware) generic code, as other architectures still use it. But we 47518049d9SSteven Rostedt (VMware) only need to keep it around for x86_64. No need to keep it 48518049d9SSteven Rostedt (VMware) for x86_32. For x86_32, force DYNAMIC_FTRACE. 49d94e0685SIngo Molnar# 50d94e0685SIngo Molnar# Arch settings 51d94e0685SIngo Molnar# 52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be 53d94e0685SIngo Molnar# ported to 32-bit as well. ) 54d94e0685SIngo Molnar# 558d5fffb9SSam Ravnborgconfig X86 563c2362e6SHarvey Harrison def_bool y 57c763ea26SIngo Molnar # 58c763ea26SIngo Molnar # Note: keep this list sorted alphabetically 59c763ea26SIngo Molnar # 606471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 616e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 62942fa985SYury Norov select ARCH_32BIT_OFF_T if X86_32 632a21ad57SThomas Gleixner select ARCH_CLOCKSOURCE_INIT 641f6d3a8fSMasami Hiramatsu select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 651e866974SAnshuman Khandual select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION 665c11f00bSDavid Hildenbrand select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 6791024b3cSAnshuman Khandual select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 68cebc774fSAnshuman Khandual select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) 691e866974SAnshuman Khandual select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE 7091dda51aSAleksey Makarov select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 71c2280be8SAnshuman Khandual select ARCH_HAS_CACHE_LINE_SIZE 722792d84eSKees Cook select ARCH_HAS_CURRENT_STACK_POINTER 73fa5b6ec9SLaura Abbott select ARCH_HAS_DEBUG_VIRTUAL 74399145f9SAnshuman Khandual select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 7521266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 76b1a57bbfSDouglas Anderson select ARCH_HAS_EARLY_DEBUG if KGDB 776471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 7872d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 796974f0c4SDaniel Micay select ARCH_HAS_FORTIFY_SOURCE 80957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 81bece04b5SMarco Elver select ARCH_HAS_KCOV if X86_64 820c9c1d56SThiago Jung Bauermann select ARCH_HAS_MEM_ENCRYPT 8310bcc80eSMathieu Desnoyers select ARCH_HAS_MEMBARRIER_SYNC_CORE 840ebeea8cSDaniel Borkmann select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 85c763ea26SIngo Molnar select ARCH_HAS_PMEM_API if X86_64 8617596731SRobin Murphy select ARCH_HAS_PTE_DEVMAP if X86_64 873010a5eaSLaurent Dufour select ARCH_HAS_PTE_SPECIAL 880aed55afSDan Williams select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 89ec6347bbSDan Williams select ARCH_HAS_COPY_MC if X86_64 90d2852a22SDaniel Borkmann select ARCH_HAS_SET_MEMORY 91d253ca0cSRick Edgecombe select ARCH_HAS_SET_DIRECT_MAP 92ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_KERNEL_RWX 93ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_MODULE_RWX 94ac1ab12aSMathieu Desnoyers select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 9525c619e5SBrian Gerst select ARCH_HAS_SYSCALL_WRAPPER 96c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 97e10cd4b0SChristoph Hellwig select ARCH_HAS_VM_GET_PAGE_PROT 987e01ccb4SZong Li select ARCH_HAS_DEBUG_WX 9963703f37SKefeng Wang select ARCH_HAS_ZONE_DMA_SET if EXPERT 1006471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 1016471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 10277fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 1035e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 1043599fe12SThomas Gleixner select ARCH_STACKWALK 1052c870e61SArnd Bergmann select ARCH_SUPPORTS_ACPI 1066471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 1075d6ad668SMike Rapoport select ARCH_SUPPORTS_DEBUG_PAGEALLOC 108d283d422SPasha Tatashin select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 1096471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 11014df3267SThomas Gleixner select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 111583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG 112583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG_THIN 1136471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 114dce44566SAnshuman Khandual select ARCH_USE_MEMTEST 1156471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 1166471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 1172ce0d7f9SMark Brown select ARCH_USE_SYM_ANNOTATIONS 118ce4a4e56SAndy Lutomirski select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 11981c22041SDaniel Borkmann select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 120c763ea26SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 12151c2ee6dSNick Desaulniers select ARCH_WANTS_NO_INSTR 12207431506SAnshuman Khandual select ARCH_WANT_GENERAL_HUGETLB 1233876d4a3SAlexandre Ghiti select ARCH_WANT_HUGE_PMD_SHARE 12447010c04SMuchun Song select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP if X86_64 12559612b24SNathan Chancellor select ARCH_WANT_LD_ORPHAN_WARN 12638d8b4e6SHuang Ying select ARCH_WANTS_THP_SWAP if X86_64 127b5f06f64SBalbir Singh select ARCH_HAS_PARANOID_L1D_FLUSH 12810916706SShile Zhang select BUILDTIME_TABLE_SORT 1296471b825SIngo Molnar select CLKEVT_I8253 1306471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 1316471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 1326471b825SIngo Molnar select DCACHE_WORD_ACCESS 1333aac3ebeSThomas Gleixner select DYNAMIC_SIGFRAME 13445471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 13545471cd9SLinus Torvalds select EDAC_SUPPORT 1366471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 1376471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 1386471b825SIngo Molnar select GENERIC_CMOS_UPDATE 1396471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 14061dc0f55SThomas Gleixner select GENERIC_CPU_VULNERABILITIES 1416471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 14227d6b4d1SThomas Gleixner select GENERIC_ENTRY 1436471b825SIngo Molnar select GENERIC_IOMAP 144c7d6c9ddSThomas Gleixner select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 1450fa115daSThomas Gleixner select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 146ad7a929fSThomas Gleixner select GENERIC_IRQ_MIGRATION if SMP 1476471b825SIngo Molnar select GENERIC_IRQ_PROBE 148c201c917SThomas Gleixner select GENERIC_IRQ_RESERVATION_MODE 1496471b825SIngo Molnar select GENERIC_IRQ_SHOW 1506471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 1512ae27137SSteven Price select GENERIC_PTDUMP 1526471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 1536471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 1547ac87074SVincenzo Frascino select GENERIC_GETTIMEOFDAY 155550a77a7SDmitry Safonov select GENERIC_VDSO_TIME_NS 15639656e83SChristoph Hellwig select GUP_GET_PTE_LOW_HIGH if X86_PAE 15717e5888eSHans de Goede select HARDIRQS_SW_RESEND 1587edaeb68SThomas Gleixner select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 1596471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 1606471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 1616471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 1626471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 1636471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 164eed1fceeSSong Liu select HAVE_ARCH_HUGE_VMALLOC if X86_64 1656471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 166b34006c4SArd Biesheuvel select HAVE_ARCH_JUMP_LABEL_RELATIVE 167d17a1d97SAndrey Ryabinin select HAVE_ARCH_KASAN if X86_64 1680609ae01SDaniel Axtens select HAVE_ARCH_KASAN_VMALLOC if X86_64 1691dc0da6eSAlexander Potapenko select HAVE_ARCH_KFENCE 1706471b825SIngo Molnar select HAVE_ARCH_KGDB 1719e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 1729e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 1731b028f78SDmitry Safonov select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 174271ca788SArd Biesheuvel select HAVE_ARCH_PREL32_RELOCATIONS 1756471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 176f7d83c1cSKees Cook select HAVE_ARCH_THREAD_STRUCT_WHITELIST 177afaef01cSAlexander Popov select HAVE_ARCH_STACKLEAK 1786471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 1796471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 180a00cc7d9SMatthew Wilcox select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 181b64d8d1eSPeter Xu select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 1827677f7fdSAxel Rasmussen select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 183e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 184fe950f60SKees Cook select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 185c763ea26SIngo Molnar select HAVE_ARCH_WITHIN_STACK_FRAMES 1862ff2b7ecSMasahiro Yamada select HAVE_ASM_MODVERSIONS 1876471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 1886471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 1896471b825SIngo Molnar select HAVE_CONTEXT_TRACKING if X86_64 190d1f250e2SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING 1916471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 19203f16cd0SJosh Poimboeuf select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL 1934ed308c4SSteven Rostedt (Google) select HAVE_BUILDTIME_MCOUNT_SORT 1946471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 1959c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 196677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 19706aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 19802a474caSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 199562955feSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 200c316eb44SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 201503e4510SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 20203f5781bSWang YanQing select HAVE_EBPF_JIT 20358340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 2046630a8e5SChristoph Hellwig select HAVE_EISA 2055f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 20667a929e0SChristoph Hellwig select HAVE_FAST_GUP 207644e0e8dSSteven Rostedt (VMware) select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 2086471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 2094a30e4c9SSteven Rostedt (VMware) select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) 2106471b825SIngo Molnar select HAVE_FUNCTION_TRACER 2116b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 2120067f129SK.Prasad select HAVE_HW_BREAKPOINT 2136471b825SIngo Molnar select HAVE_IOREMAP_PROT 214624db9eaSThomas Gleixner select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 2156471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 2164ab7674fSJosh Poimboeuf select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL 2176471b825SIngo Molnar select HAVE_KERNEL_BZIP2 2186471b825SIngo Molnar select HAVE_KERNEL_GZIP 2196471b825SIngo Molnar select HAVE_KERNEL_LZ4 2206471b825SIngo Molnar select HAVE_KERNEL_LZMA 2216471b825SIngo Molnar select HAVE_KERNEL_LZO 2226471b825SIngo Molnar select HAVE_KERNEL_XZ 223fb46d057SNick Terrell select HAVE_KERNEL_ZSTD 2246471b825SIngo Molnar select HAVE_KPROBES 2256471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 226540adea3SMasami Hiramatsu select HAVE_FUNCTION_ERROR_INJECTION 2276471b825SIngo Molnar select HAVE_KRETPROBES 228f3a112c0SMasami Hiramatsu select HAVE_RETHOOK 2296471b825SIngo Molnar select HAVE_KVM 2306471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 2310102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 232ee9f8fceSJosh Poimboeuf select HAVE_MOD_ARCH_SPECIFIC 2339f132f7eSJoel Fernandes (Google) select HAVE_MOVE_PMD 234be37c98dSKalesh Singh select HAVE_MOVE_PUD 23522102f45SJosh Poimboeuf select HAVE_NOINSTR_HACK if HAVE_OBJTOOL 23642a0bb3fSPetr Mladek select HAVE_NMI 237489e355bSJosh Poimboeuf select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL 23803f16cd0SJosh Poimboeuf select HAVE_OBJTOOL if X86_64 2396471b825SIngo Molnar select HAVE_OPTPROBES 2406471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 2416471b825SIngo Molnar select HAVE_PERF_EVENTS 242c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 24392e5aae4SNicholas Piggin select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 244eb01d42aSChristoph Hellwig select HAVE_PCI 245c5e63197SJiri Olsa select HAVE_PERF_REGS 246c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 247ff2e6d72SPeter Zijlstra select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 24800998085SThomas Gleixner select HAVE_POSIX_CPU_TIMERS_TASK_WORK 2496471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 25003f16cd0SJosh Poimboeuf select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION 2513c88ee19SMasami Hiramatsu select HAVE_FUNCTION_ARG_ACCESS_API 2527ecd19cfSKefeng Wang select HAVE_SETUP_PER_CPU_AREA 253cd1a41ceSThomas Gleixner select HAVE_SOFTIRQ_ON_OWN_STACK 254d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 25503f16cd0SJosh Poimboeuf select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 256e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 25703f16cd0SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL 25899cf983cSMark Rutland select HAVE_PREEMPT_DYNAMIC_CALL 259d6761b8fSMathieu Desnoyers select HAVE_RSEQ 2606471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2615f3da8c0SJosh Poimboeuf select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL 2626471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2637c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 2647ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 26505736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 266c0185808SThomas Gleixner select IRQ_FORCED_THREADING 2677ecd19cfSKefeng Wang select NEED_PER_CPU_EMBED_FIRST_CHUNK 2687ecd19cfSKefeng Wang select NEED_PER_CPU_PAGE_FIRST_CHUNK 26986596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 2702eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 271625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 2726471b825SIngo Molnar select PERF_EVENTS 2733195ef59SPrarit Bhargava select RTC_LIB 274d6faca40SArnd Bergmann select RTC_MC146818_LIB 2756471b825SIngo Molnar select SPARSE_IRQ 27683fe27eaSPranith Kumar select SRCU 2776471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 27815f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 2794aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT 2806471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 2816471b825SIngo Molnar select VIRT_TO_BUS 2823b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 2836471b825SIngo Molnar select X86_FEATURE_NAMES if PROC_FS 2840c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 28550468e43SJarkko Sakkinen select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX 2869e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 2877d8330a5SBalbir Singh 288ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 2893120e25eSJan Beulich def_bool y 2903120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 291ba7e4d13SIngo Molnar 29251b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 29351b26adaSLinus Torvalds string 29451b26adaSLinus Torvalds default "elf32-i386" if X86_32 29551b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 29651b26adaSLinus Torvalds 2978d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 2983c2362e6SHarvey Harrison def_bool y 2998d5fffb9SSam Ravnborg 3008d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 3013c2362e6SHarvey Harrison def_bool y 3028d5fffb9SSam Ravnborg 3038d5fffb9SSam Ravnborgconfig MMU 3043c2362e6SHarvey Harrison def_bool y 3058d5fffb9SSam Ravnborg 3069e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 3079e08f57dSDaniel Cashman default 28 if 64BIT 3089e08f57dSDaniel Cashman default 8 3099e08f57dSDaniel Cashman 3109e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 3119e08f57dSDaniel Cashman default 32 if 64BIT 3129e08f57dSDaniel Cashman default 16 3139e08f57dSDaniel Cashman 3149e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 3159e08f57dSDaniel Cashman default 8 3169e08f57dSDaniel Cashman 3179e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 3189e08f57dSDaniel Cashman default 16 3199e08f57dSDaniel Cashman 3208d5fffb9SSam Ravnborgconfig SBUS 3218d5fffb9SSam Ravnborg bool 3228d5fffb9SSam Ravnborg 3238d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 3243120e25eSJan Beulich def_bool y 3253120e25eSJan Beulich depends on ISA_DMA_API 3268d5fffb9SSam Ravnborg 3278d5fffb9SSam Ravnborgconfig GENERIC_BUG 3283c2362e6SHarvey Harrison def_bool y 3298d5fffb9SSam Ravnborg depends on BUG 330b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 331b93a531eSJan Beulich 332b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 333b93a531eSJan Beulich bool 3348d5fffb9SSam Ravnborg 3358d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 3363120e25eSJan Beulich def_bool y 3373120e25eSJan Beulich depends on ISA_DMA_API 3388d5fffb9SSam Ravnborg 3391032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 3401032c0baSSam Ravnborg def_bool y 3411032c0baSSam Ravnborg 3429a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3439a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3448d5fffb9SSam Ravnborg 345801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 346801e4062SJohannes Berg def_bool y 347801e4062SJohannes Berg 348d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO 349d7109fe3SAndy Shevchenko int 350d7109fe3SAndy Shevchenko default 1024 if X86_64 351d7109fe3SAndy Shevchenko default 512 352d7109fe3SAndy Shevchenko 353f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 354f4cb5700SJohannes Berg def_bool y 355f4cb5700SJohannes Berg 3568d5fffb9SSam Ravnborgconfig AUDIT_ARCH 357e0fd24a3SJan Beulich def_bool y if X86_64 3588d5fffb9SSam Ravnborg 359d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 360d6f2d75aSAndrey Ryabinin hex 361d6f2d75aSAndrey Ryabinin depends on KASAN 362d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 363d6f2d75aSAndrey Ryabinin 36469575d38SShane Wangconfig HAVE_INTEL_TXT 36569575d38SShane Wang def_bool y 3666ea30386SKees Cook depends on INTEL_IOMMU && ACPI 36769575d38SShane Wang 3686b0c3d44SSam Ravnborgconfig X86_32_SMP 3696b0c3d44SSam Ravnborg def_bool y 3706b0c3d44SSam Ravnborg depends on X86_32 && SMP 3716b0c3d44SSam Ravnborg 3726b0c3d44SSam Ravnborgconfig X86_64_SMP 3736b0c3d44SSam Ravnborg def_bool y 3746b0c3d44SSam Ravnborg depends on X86_64 && SMP 3756b0c3d44SSam Ravnborg 3762b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3772b144498SSrikar Dronamraju def_bool y 3782b144498SSrikar Dronamraju 379d20642f0SRob Herringconfig FIX_EARLYCON_MEM 380d20642f0SRob Herring def_bool y 381d20642f0SRob Herring 38294d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 38394d49eb3SKirill A. Shutemov bool 38494d49eb3SKirill A. Shutemov 38598233368SKirill A. Shutemovconfig PGTABLE_LEVELS 38698233368SKirill A. Shutemov int 38777ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 38898233368SKirill A. Shutemov default 4 if X86_64 38998233368SKirill A. Shutemov default 3 if X86_PAE 39098233368SKirill A. Shutemov default 2 39198233368SKirill A. Shutemov 3922a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 3932a61f474SMasahiro Yamada bool 394*1b866781SNathan Chancellor default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT 395*1b866781SNathan Chancellor default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) 3962a61f474SMasahiro Yamada help 3972a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 3983fb0fdb3SAndy Lutomirski the compiler produces broken code or if it does not let us control 3993fb0fdb3SAndy Lutomirski the segment on 32-bit kernels. 4002a61f474SMasahiro Yamada 401506f1d07SSam Ravnborgmenu "Processor type and features" 402506f1d07SSam Ravnborg 403506f1d07SSam Ravnborgconfig SMP 404506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 405a7f7f624SMasahiro Yamada help 406506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 4074a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 4084a474157SRobert Graffham than one CPU, say Y. 409506f1d07SSam Ravnborg 4104a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 411506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 412506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4134a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 414506f1d07SSam Ravnborg will run faster if you say N here. 415506f1d07SSam Ravnborg 416506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 417506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 418506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 419506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 420506f1d07SSam Ravnborg 421506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 422506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 423506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 424506f1d07SSam Ravnborg 425cb1aaebeSMauro Carvalho Chehab See also <file:Documentation/x86/i386/IO-APIC.rst>, 4264f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 427506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 428506f1d07SSam Ravnborg 429506f1d07SSam Ravnborg If you don't know what to do here, say N. 430506f1d07SSam Ravnborg 4319def39beSJosh Triplettconfig X86_FEATURE_NAMES 4329def39beSJosh Triplett bool "Processor feature human-readable names" if EMBEDDED 4339def39beSJosh Triplett default y 434a7f7f624SMasahiro Yamada help 4359def39beSJosh Triplett This option compiles in a table of x86 feature bits and corresponding 4369def39beSJosh Triplett names. This is required to support /proc/cpuinfo and a few kernel 4379def39beSJosh Triplett messages. You can disable this to save space, at the expense of 4389def39beSJosh Triplett making those few kernel messages show numeric feature bits instead. 4399def39beSJosh Triplett 4409def39beSJosh Triplett If in doubt, say Y. 4419def39beSJosh Triplett 44206cd9a7dSYinghai Luconfig X86_X2APIC 44306cd9a7dSYinghai Lu bool "Support x2apic" 44419e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 445a7f7f624SMasahiro Yamada help 44606cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 44706cd9a7dSYinghai Lu 44806cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 44906cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 45006cd9a7dSYinghai Lu 45106cd9a7dSYinghai Lu If you don't know what to do here, say N. 45206cd9a7dSYinghai Lu 4536695c85bSYinghai Luconfig X86_MPPARSE 4544590d98fSAndy Shevchenko bool "Enable MPS table" if ACPI 4557a527688SJan Beulich default y 4565ab74722SIngo Molnar depends on X86_LOCAL_APIC 457a7f7f624SMasahiro Yamada help 4586695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4596695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4606695c85bSYinghai Lu 461ddd70cf9SJun Nakajimaconfig GOLDFISH 462ddd70cf9SJun Nakajima def_bool y 463ddd70cf9SJun Nakajima depends on X86_GOLDFISH 464ddd70cf9SJun Nakajima 46576b04384SDavid Woodhouseconfig RETPOLINE 46676b04384SDavid Woodhouse bool "Avoid speculative indirect branches in kernel" 46703f16cd0SJosh Poimboeuf select OBJTOOL if HAVE_OBJTOOL 46876b04384SDavid Woodhouse default y 46976b04384SDavid Woodhouse help 47076b04384SDavid Woodhouse Compile kernel with the retpoline compiler options to guard against 47176b04384SDavid Woodhouse kernel-to-user data leaks by avoiding speculative indirect 47276b04384SDavid Woodhouse branches. Requires a compiler with -mindirect-branch=thunk-extern 47376b04384SDavid Woodhouse support for full protection. The kernel may run slower. 47476b04384SDavid Woodhouse 475e463a09aSPeter Zijlstraconfig CC_HAS_SLS 476e463a09aSPeter Zijlstra def_bool $(cc-option,-mharden-sls=all) 477e463a09aSPeter Zijlstra 478e463a09aSPeter Zijlstraconfig SLS 479e463a09aSPeter Zijlstra bool "Mitigate Straight-Line-Speculation" 480e463a09aSPeter Zijlstra depends on CC_HAS_SLS && X86_64 48103f16cd0SJosh Poimboeuf select OBJTOOL if HAVE_OBJTOOL 482e463a09aSPeter Zijlstra default n 483e463a09aSPeter Zijlstra help 484e463a09aSPeter Zijlstra Compile the kernel with straight-line-speculation options to guard 485e463a09aSPeter Zijlstra against straight line speculation. The kernel image might be slightly 486e463a09aSPeter Zijlstra larger. 487e463a09aSPeter Zijlstra 488e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 489e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4906fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 49159fe5a77SThomas Gleixner select KERNFS 492e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 49378e99b4aSFenghua Yu help 494e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4956fe07ce3SBabu Moger 4966fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4976fe07ce3SBabu Moger usage by the CPU. 4986fe07ce3SBabu Moger 4996fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 5006fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 5016fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 5026fe07ce3SBabu Moger 5036fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 5046fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 5056fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 50678e99b4aSFenghua Yu 50778e99b4aSFenghua Yu Say N if unsure. 50878e99b4aSFenghua Yu 5098425091fSRavikiran G Thirumalaiif X86_32 510a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 511a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 512a0d0bb4dSRandy Dunlap depends on SMP 513a7f7f624SMasahiro Yamada help 514e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 515a0d0bb4dSRandy Dunlap 516c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 517c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 518c5c606d9SRavikiran G Thirumalai default y 519a7f7f624SMasahiro Yamada help 52006ac8346SIngo Molnar If you disable this option then the kernel will only support 52106ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 52206ac8346SIngo Molnar systems out there.) 52306ac8346SIngo Molnar 5248425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5258425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 526cb7b8023SBen Hutchings Goldfish (Android emulator) 5278425091fSRavikiran G Thirumalai AMD Elan 5288425091fSRavikiran G Thirumalai RDC R-321x SoC 5298425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 53083125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5313f4110a4SThomas Gleixner Moorestown MID devices 53206ac8346SIngo Molnar 53306ac8346SIngo Molnar If you have one of these systems, or if you want to build a 53406ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 535758cd94aSJuerg Haefligerendif # X86_32 53606ac8346SIngo Molnar 5378425091fSRavikiran G Thirumalaiif X86_64 5388425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5398425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5408425091fSRavikiran G Thirumalai default y 541a7f7f624SMasahiro Yamada help 5428425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5438425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5448425091fSRavikiran G Thirumalai systems out there.) 5458425091fSRavikiran G Thirumalai 5468425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5478425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 54844b111b5SSteffen Persvold Numascale NumaChip 5498425091fSRavikiran G Thirumalai ScaleMP vSMP 5508425091fSRavikiran G Thirumalai SGI Ultraviolet 5518425091fSRavikiran G Thirumalai 5528425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5538425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 554758cd94aSJuerg Haefligerendif # X86_64 555c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 556c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 55744b111b5SSteffen Persvoldconfig X86_NUMACHIP 55844b111b5SSteffen Persvold bool "Numascale NumaChip" 55944b111b5SSteffen Persvold depends on X86_64 56044b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 56144b111b5SSteffen Persvold depends on NUMA 56244b111b5SSteffen Persvold depends on SMP 56344b111b5SSteffen Persvold depends on X86_X2APIC 564f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 565a7f7f624SMasahiro Yamada help 56644b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 56744b111b5SSteffen Persvold enable more than ~168 cores. 56844b111b5SSteffen Persvold If you don't have one of these, you should say N here. 56903b48632SNick Piggin 5706a48565eSIngo Molnarconfig X86_VSMP 571c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5726276a074SBorislav Petkov select HYPERVISOR_GUEST 5736a48565eSIngo Molnar select PARAVIRT 5746a48565eSIngo Molnar depends on X86_64 && PCI 575c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 576ead91d4bSShai Fultheim depends on SMP 577a7f7f624SMasahiro Yamada help 5786a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5796a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5806a48565eSIngo Molnar if you have one of these machines. 5816a48565eSIngo Molnar 582c5c606d9SRavikiran G Thirumalaiconfig X86_UV 583c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 584c5c606d9SRavikiran G Thirumalai depends on X86_64 585c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 58654c28d29SJack Steiner depends on NUMA 5871ecb4ae5SAndrew Morton depends on EFI 588c2209ea5SIngo Molnar depends on KEXEC_CORE 5899d6c26e7SSuresh Siddha depends on X86_X2APIC 5901222e564SIngo Molnar depends on PCI 591a7f7f624SMasahiro Yamada help 592c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 593c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 594c5c606d9SRavikiran G Thirumalai 595c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 596c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 597506f1d07SSam Ravnborg 598ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 599ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 600cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 601a7f7f624SMasahiro Yamada help 602ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 603ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 604ddd70cf9SJun Nakajima Goldfish emulator say N here. 605ddd70cf9SJun Nakajima 606c751e17bSThomas Gleixnerconfig X86_INTEL_CE 607c751e17bSThomas Gleixner bool "CE4100 TV platform" 608c751e17bSThomas Gleixner depends on PCI 609c751e17bSThomas Gleixner depends on PCI_GODIRECT 6106084a6e2SJiang Liu depends on X86_IO_APIC 611c751e17bSThomas Gleixner depends on X86_32 612c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 61337bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 614da6b737bSSebastian Andrzej Siewior select OF 615da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 616a7f7f624SMasahiro Yamada help 617c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 618c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 619c751e17bSThomas Gleixner boxes and media devices. 620c751e17bSThomas Gleixner 6214cb9b00fSDavid Cohenconfig X86_INTEL_MID 62243605ef1SAlan Cox bool "Intel MID platform support" 62343605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 624edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6251ea7c673SAlan Cox depends on PCI 6263fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6271ea7c673SAlan Cox depends on X86_IO_APIC 6284cb9b00fSDavid Cohen select I2C 6297c9c3a1eSAlan Cox select DW_APB_TIMER 63054b34aa0SMika Westerberg select INTEL_SCU_PCI 631a7f7f624SMasahiro Yamada help 6324cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6334cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6344cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6351ea7c673SAlan Cox 6364cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6374cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 63843605ef1SAlan Cox 6398bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6408bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6418bbc2a13SBryan O'Donoghue depends on X86_32 6428bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6438bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6448bbc2a13SBryan O'Donoghue depends on X86_TSC 6458bbc2a13SBryan O'Donoghue depends on PCI 6468bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6478bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6488bbc2a13SBryan O'Donoghue select IOSF_MBI 6498bbc2a13SBryan O'Donoghue select INTEL_IMR 6509ab6eb51SAndy Shevchenko select COMMON_CLK 651a7f7f624SMasahiro Yamada help 6528bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6538bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6548bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6558bbc2a13SBryan O'Donoghue 6563d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6573d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6585962dd22SSinan Kaya depends on X86 && ACPI && PCI 6593d48aab1SMika Westerberg select COMMON_CLK 6600f531431SMathias Nyman select PINCTRL 661eebb3e8dSAndy Shevchenko select IOSF_MBI 662a7f7f624SMasahiro Yamada help 6633d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6643d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6650f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6660f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6673d48aab1SMika Westerberg 66892082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 66992082a88SKen Xue bool "AMD ACPI2Platform devices support" 67092082a88SKen Xue depends on ACPI 67192082a88SKen Xue select COMMON_CLK 67292082a88SKen Xue select PINCTRL 673a7f7f624SMasahiro Yamada help 67492082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 67592082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 67692082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 67792082a88SKen Xue implemented under PINCTRL subsystem. 67892082a88SKen Xue 679ced3ce76SDavid E. Boxconfig IOSF_MBI 680ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 681ced3ce76SDavid E. Box depends on PCI 682a7f7f624SMasahiro Yamada help 683ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 684ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 685ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 686ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 687ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 688ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 689ced3ce76SDavid E. Box This list is not meant to be exclusive. 690ced3ce76SDavid E. Box - BayTrail 691ced3ce76SDavid E. Box - Braswell 692ced3ce76SDavid E. Box - Quark 693ced3ce76SDavid E. Box 694ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 695ced3ce76SDavid E. Box 696ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 697ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 698ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 699a7f7f624SMasahiro Yamada help 700ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 701ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 702ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 703ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 704ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 705ed2226bdSDavid E. Box device they want to access. 706ed2226bdSDavid E. Box 707ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 708ed2226bdSDavid E. Box 709c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 710c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 711506f1d07SSam Ravnborg depends on X86_32 712c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 713c5c606d9SRavikiran G Thirumalai select M486 714c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 715a7f7f624SMasahiro Yamada help 716c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 717c5c606d9SRavikiran G Thirumalai as R-8610-(G). 718c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 719c5c606d9SRavikiran G Thirumalai 720e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7219c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7229c398017SIngo Molnar depends on X86_32 && SMP 723c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 724a7f7f624SMasahiro Yamada help 725b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 726b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 727b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 728b5660ba7SH. Peter Anvin one and will fallback to default. 729d49c4288SYinghai Lu 730c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 731d49c4288SYinghai Lu 732d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7336fc108a0SJan Beulich def_bool y 734d949f36fSLinus Torvalds # MCE code calls memory_failure(): 735d949f36fSLinus Torvalds depends on X86_MCE 736d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 737d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 738d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 739d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 740d949f36fSLinus Torvalds 74183125a3aSAlessandro Rubiniconfig STA2X11 74283125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 74383125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 74483125a3aSAlessandro Rubini select SWIOTLB 74583125a3aSAlessandro Rubini select MFD_STA2X11 7460145071bSLinus Walleij select GPIOLIB 747a7f7f624SMasahiro Yamada help 74883125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 74983125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 75083125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 75183125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 75283125a3aSAlessandro Rubini standard PC machines. 75383125a3aSAlessandro Rubini 75482148d1dSShérabconfig X86_32_IRIS 75582148d1dSShérab tristate "Eurobraille/Iris poweroff module" 75682148d1dSShérab depends on X86_32 757a7f7f624SMasahiro Yamada help 75882148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 75982148d1dSShérab to shut themselves down properly. A special I/O sequence is 76082148d1dSShérab needed to do so, which is what this module does at 76182148d1dSShérab kernel shutdown. 76282148d1dSShérab 76382148d1dSShérab This is only for Iris machines from EuroBraille. 76482148d1dSShérab 76582148d1dSShérab If unused, say N. 76682148d1dSShérab 767ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7683c2362e6SHarvey Harrison def_bool y 7693c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 770a87d0914SKen Chen depends on X86 771a7f7f624SMasahiro Yamada help 772506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 773506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 774506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 775506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 776506f1d07SSam Ravnborg 777506f1d07SSam Ravnborg If in doubt, say "Y". 778506f1d07SSam Ravnborg 7796276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7806276a074SBorislav Petkov bool "Linux guest support" 781a7f7f624SMasahiro Yamada help 7826276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7836276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7846276a074SBorislav Petkov setup. 785506f1d07SSam Ravnborg 7866276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7876276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 788506f1d07SSam Ravnborg 7896276a074SBorislav Petkovif HYPERVISOR_GUEST 790506f1d07SSam Ravnborg 791e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 792e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 793a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 794a7f7f624SMasahiro Yamada help 795e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 796e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 797e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 798e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 799e61bd94aSEduardo Pereira Habkost 800c00a280aSJuergen Grossconfig PARAVIRT_XXL 801c00a280aSJuergen Gross bool 802c00a280aSJuergen Gross 8036276a074SBorislav Petkovconfig PARAVIRT_DEBUG 8046276a074SBorislav Petkov bool "paravirt-ops debugging" 8056276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 806a7f7f624SMasahiro Yamada help 8076276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 8086276a074SBorislav Petkov a paravirt_op is missing when it is called. 8096276a074SBorislav Petkov 810b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 811b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 8126ea30386SKees Cook depends on PARAVIRT && SMP 813a7f7f624SMasahiro Yamada help 814b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 815b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 816b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 817b4ecc126SJeremy Fitzhardinge 8184c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8194c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 820b4ecc126SJeremy Fitzhardinge 8214c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 822b4ecc126SJeremy Fitzhardinge 823ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 824ecca2502SZhao Yakui def_bool n 825ecca2502SZhao Yakui 8266276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8276276a074SBorislav Petkov 8286276a074SBorislav Petkovconfig KVM_GUEST 8296276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8306276a074SBorislav Petkov depends on PARAVIRT 8316276a074SBorislav Petkov select PARAVIRT_CLOCK 832a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 833b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8346276a074SBorislav Petkov default y 835a7f7f624SMasahiro Yamada help 8366276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8376276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8386276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8396276a074SBorislav Petkov underlying device model, the host provides the guest with 8406276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8416276a074SBorislav Petkov 842a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 843a1c4423bSMarcelo Tosatti def_bool n 844a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 845a1c4423bSMarcelo Tosatti help 846a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 847a1c4423bSMarcelo Tosatti 8487733607fSMaran Wilsonconfig PVH 8497733607fSMaran Wilson bool "Support for running PVH guests" 850a7f7f624SMasahiro Yamada help 8517733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8527733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8537733607fSMaran Wilson 8546276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8556276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8566276a074SBorislav Petkov depends on PARAVIRT 857a7f7f624SMasahiro Yamada help 8586276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8596276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8606276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8616276a074SBorislav Petkov that, there can be a small performance impact. 8626276a074SBorislav Petkov 8636276a074SBorislav Petkov If in doubt, say N here. 8646276a074SBorislav Petkov 8657af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8667af192c9SGerd Hoffmann bool 8677af192c9SGerd Hoffmann 8684a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8694a362601SJan Kiszka bool "Jailhouse non-root cell support" 870abde587bSArnd Bergmann depends on X86_64 && PCI 87187e65d05SJan Kiszka select X86_PM_TIMER 872a7f7f624SMasahiro Yamada help 8734a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8744a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8754a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8764a362601SJan Kiszka 877ec7972c9SZhao Yakuiconfig ACRN_GUEST 878ec7972c9SZhao Yakui bool "ACRN Guest support" 879ec7972c9SZhao Yakui depends on X86_64 880498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 881ec7972c9SZhao Yakui help 882ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 883ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 884ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 885ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 886ec7972c9SZhao Yakui found in https://projectacrn.org/. 887ec7972c9SZhao Yakui 88859bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST 88959bd54a8SKuppuswamy Sathyanarayanan bool "Intel TDX (Trust Domain Extensions) - Guest Support" 89059bd54a8SKuppuswamy Sathyanarayanan depends on X86_64 && CPU_SUP_INTEL 89159bd54a8SKuppuswamy Sathyanarayanan depends on X86_X2APIC 89241394e33SKirill A. Shutemov select ARCH_HAS_CC_PLATFORM 893968b4931SKirill A. Shutemov select X86_MEM_ENCRYPT 89477a512e3SSean Christopherson select X86_MCE 89559bd54a8SKuppuswamy Sathyanarayanan help 89659bd54a8SKuppuswamy Sathyanarayanan Support running as a guest under Intel TDX. Without this support, 89759bd54a8SKuppuswamy Sathyanarayanan the guest kernel can not boot or run under TDX. 89859bd54a8SKuppuswamy Sathyanarayanan TDX includes memory encryption and integrity capabilities 89959bd54a8SKuppuswamy Sathyanarayanan which protect the confidentiality and integrity of guest 90059bd54a8SKuppuswamy Sathyanarayanan memory contents and CPU state. TDX guests are protected from 90159bd54a8SKuppuswamy Sathyanarayanan some attacks from the VMM. 90259bd54a8SKuppuswamy Sathyanarayanan 9036276a074SBorislav Petkovendif # HYPERVISOR_GUEST 90497349135SJeremy Fitzhardinge 905506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 906506f1d07SSam Ravnborg 907506f1d07SSam Ravnborgconfig HPET_TIMER 9083c2362e6SHarvey Harrison def_bool X86_64 909506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 910a7f7f624SMasahiro Yamada help 911506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 912506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 913506f1d07SSam Ravnborg present. 914506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 915506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 916506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 9174e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 9184e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 919506f1d07SSam Ravnborg 920506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 921506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 922506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 923506f1d07SSam Ravnborg 924506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 925506f1d07SSam Ravnborg 926506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 9273c2362e6SHarvey Harrison def_bool y 9283228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 929506f1d07SSam Ravnborg 9306a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 931506f1d07SSam Ravnborg# The code disables itself when not needed. 9327ae9392cSThomas Petazzoniconfig DMI 9337ae9392cSThomas Petazzoni default y 934cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9356a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 936a7f7f624SMasahiro Yamada help 9377ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9387ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9397ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9407ae9392cSThomas Petazzoni BIOS code. 9417ae9392cSThomas Petazzoni 942506f1d07SSam Ravnborgconfig GART_IOMMU 94338901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9442f9237d4SChristoph Hellwig select DMA_OPS 945a4ce5a48SChristoph Hellwig select IOMMU_HELPER 946506f1d07SSam Ravnborg select SWIOTLB 94723ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 948a7f7f624SMasahiro Yamada help 949ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 950ced3c42cSIngo Molnar GART based hardware IOMMUs. 951ced3c42cSIngo Molnar 952ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 953ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 954ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 955ced3c42cSIngo Molnar 956ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 957ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 958ced3c42cSIngo Molnar 959ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 960ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 961ced3c42cSIngo Molnar 32-bit limited device. 962ced3c42cSIngo Molnar 963ced3c42cSIngo Molnar If unsure, say Y. 964506f1d07SSam Ravnborg 9658b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT 9668b766b0fSMichal Suchanek bool 9678b766b0fSMichal Suchanek help 9688b766b0fSMichal Suchanek If true, at least one selected framebuffer driver can take advantage 9698b766b0fSMichal Suchanek of VESA video modes set at an early boot stage via the vga= parameter. 9708b766b0fSMichal Suchanek 9711184dc2fSMike Travisconfig MAXSMP 972ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9736ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 97436f5101aSMike Travis select CPUMASK_OFFSTACK 975a7f7f624SMasahiro Yamada help 976ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9771184dc2fSMike Travis If unsure, say N. 978506f1d07SSam Ravnborg 979aec6487eSIngo Molnar# 980aec6487eSIngo Molnar# The maximum number of CPUs supported: 981aec6487eSIngo Molnar# 982aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 983aec6487eSIngo Molnar# and which can be configured interactively in the 984aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 985aec6487eSIngo Molnar# 986aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 987aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 988aec6487eSIngo Molnar# 989aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 990aec6487eSIngo Molnar# interactive configuration. ) 991aec6487eSIngo Molnar# 992a0d0bb4dSRandy Dunlap 993aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 994a0d0bb4dSRandy Dunlap int 995aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 996a0d0bb4dSRandy Dunlap default 1 if !SMP 997a0d0bb4dSRandy Dunlap default 2 998a0d0bb4dSRandy Dunlap 999aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 1000a0d0bb4dSRandy Dunlap int 1001a0d0bb4dSRandy Dunlap depends on X86_32 1002aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 1003aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 1004a0d0bb4dSRandy Dunlap default 1 if !SMP 1005a0d0bb4dSRandy Dunlap 1006aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 1007a0d0bb4dSRandy Dunlap int 1008a0d0bb4dSRandy Dunlap depends on X86_64 10091edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 10101edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 1011a0d0bb4dSRandy Dunlap default 1 if !SMP 1012aec6487eSIngo Molnar 1013aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 1014aec6487eSIngo Molnar int 1015aec6487eSIngo Molnar depends on X86_32 1016aec6487eSIngo Molnar default 32 if X86_BIGSMP 1017aec6487eSIngo Molnar default 8 if SMP 1018aec6487eSIngo Molnar default 1 if !SMP 1019aec6487eSIngo Molnar 1020aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 1021aec6487eSIngo Molnar int 1022aec6487eSIngo Molnar depends on X86_64 1023a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 1024a0d0bb4dSRandy Dunlap default 64 if SMP 1025aec6487eSIngo Molnar default 1 if !SMP 1026a0d0bb4dSRandy Dunlap 1027506f1d07SSam Ravnborgconfig NR_CPUS 102836f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 1029aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1030aec6487eSIngo Molnar default NR_CPUS_DEFAULT 1031a7f7f624SMasahiro Yamada help 1032506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 1033bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1034cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 1035506f1d07SSam Ravnborg minimum value which makes sense is 2. 1036506f1d07SSam Ravnborg 1037aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1038aec6487eSIngo Molnar to the kernel image. 1039506f1d07SSam Ravnborg 104066558b73STim Chenconfig SCHED_CLUSTER 104166558b73STim Chen bool "Cluster scheduler support" 104266558b73STim Chen depends on SMP 104366558b73STim Chen default y 104466558b73STim Chen help 104566558b73STim Chen Cluster scheduler support improves the CPU scheduler's decision 104666558b73STim Chen making when dealing with machines that have clusters of CPUs. 104766558b73STim Chen Cluster usually means a couple of CPUs which are placed closely 104866558b73STim Chen by sharing mid-level caches, last-level cache tags or internal 104966558b73STim Chen busses. 105066558b73STim Chen 1051506f1d07SSam Ravnborgconfig SCHED_SMT 1052dbe73364SThomas Gleixner def_bool y if SMP 1053506f1d07SSam Ravnborg 1054506f1d07SSam Ravnborgconfig SCHED_MC 10553c2362e6SHarvey Harrison def_bool y 10563c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1057c8e56d20SBorislav Petkov depends on SMP 1058a7f7f624SMasahiro Yamada help 1059506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1060506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1061506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1062506f1d07SSam Ravnborg 1063de966cf4STim Chenconfig SCHED_MC_PRIO 1064de966cf4STim Chen bool "CPU core priorities scheduler support" 10650a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10660a21fc12SIngo Molnar select X86_INTEL_PSTATE 10670a21fc12SIngo Molnar select CPU_FREQ 1068de966cf4STim Chen default y 1069a7f7f624SMasahiro Yamada help 1070de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1071de966cf4STim Chen core ordering determined at manufacturing time, which allows 1072de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1073de966cf4STim Chen single threaded workloads) than others. 1074de966cf4STim Chen 1075de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1076de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1077de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1078de966cf4STim Chen overall system performance can be achieved. 1079de966cf4STim Chen 1080de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1081de966cf4STim Chen 1082de966cf4STim Chen If unsure say Y here. 10835e76b2abSTim Chen 108430b8b006SThomas Gleixnerconfig UP_LATE_INIT 108530b8b006SThomas Gleixner def_bool y 1086ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 108730b8b006SThomas Gleixner 1088506f1d07SSam Ravnborgconfig X86_UP_APIC 108950849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 109050849eefSJan Beulich default PCI_MSI 109138a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1092a7f7f624SMasahiro Yamada help 1093506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1094506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1095506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1096506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1097506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1098506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1099506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1100506f1d07SSam Ravnborg lockups. 1101506f1d07SSam Ravnborg 1102506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1103506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1104506f1d07SSam Ravnborg depends on X86_UP_APIC 1105a7f7f624SMasahiro Yamada help 1106506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1107506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1108506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1109506f1d07SSam Ravnborg 1110506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1111506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1112506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1113506f1d07SSam Ravnborg 1114506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 11153c2362e6SHarvey Harrison def_bool y 11160dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1117b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 111852f518a3SJiang Liu select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1119506f1d07SSam Ravnborg 1120506f1d07SSam Ravnborgconfig X86_IO_APIC 1121b1da1e71SJan Beulich def_bool y 1122b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1123506f1d07SSam Ravnborg 112441b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 112541b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 112641b9eb26SStefan Assmann depends on X86_IO_APIC 1127a7f7f624SMasahiro Yamada help 112841b9eb26SStefan Assmann This option enables a workaround that fixes a source of 112941b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 113041b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 113141b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 113241b9eb26SStefan Assmann 113341b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 113441b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 113541b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 113641b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 113741b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 113841b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 113941b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 114041b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 114141b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 114241b9eb26SStefan Assmann down (vital) interrupt lines. 114341b9eb26SStefan Assmann 114441b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 114541b9eb26SStefan Assmann increased on these systems. 114641b9eb26SStefan Assmann 1147506f1d07SSam Ravnborgconfig X86_MCE 1148bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1149648ed940SChen, Gong select GENERIC_ALLOCATOR 1150e57dbaf7SBorislav Petkov default y 1151a7f7f624SMasahiro Yamada help 1152bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1153bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1154506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1155bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11564efc0670SAndi Kleen 11575de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11585de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11595de97c9fSTony Luck depends on X86_MCE 1160a7f7f624SMasahiro Yamada help 11615de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11625de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11635de97c9fSTony Luck rasdaemon solution. 11645de97c9fSTony Luck 1165506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11663c2362e6SHarvey Harrison def_bool y 11673c2362e6SHarvey Harrison prompt "Intel MCE features" 1168c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1169a7f7f624SMasahiro Yamada help 1170506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1171506f1d07SSam Ravnborg the thermal monitor. 1172506f1d07SSam Ravnborg 1173506f1d07SSam Ravnborgconfig X86_MCE_AMD 11743c2362e6SHarvey Harrison def_bool y 11753c2362e6SHarvey Harrison prompt "AMD MCE features" 1176f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1177a7f7f624SMasahiro Yamada help 1178506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1179506f1d07SSam Ravnborg the DRAM Error Threshold. 1180506f1d07SSam Ravnborg 11814efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11826fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1183c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1184a7f7f624SMasahiro Yamada help 11854efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11865065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11874efc0670SAndi Kleen line. 11884efc0670SAndi Kleen 1189b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1190b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11916fc108a0SJan Beulich def_bool y 1192b2762686SAndi Kleen 1193ea149b36SAndi Kleenconfig X86_MCE_INJECT 1194bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1195ea149b36SAndi Kleen tristate "Machine check injector support" 1196a7f7f624SMasahiro Yamada help 1197ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1198ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1199ea149b36SAndi Kleen QA it is safe to say n. 1200ea149b36SAndi Kleen 120107dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1202e633c65aSKan Liang 12035aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 12041e642812SIngo Molnar bool "Legacy VM86 support" 1205506f1d07SSam Ravnborg depends on X86_32 1206a7f7f624SMasahiro Yamada help 12075aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 12085aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 12095aef51c3SAndy Lutomirski 12105aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 12115aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 12125aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 12135aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 12145aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 12151e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 12161e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 12171e642812SIngo Molnar mode might be faster than emulation and you might want to 12181e642812SIngo Molnar enable this option. 12195aef51c3SAndy Lutomirski 12201e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 12211e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 12221e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 12231e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 12245aef51c3SAndy Lutomirski 12251e642812SIngo Molnar Enabling this option increases the complexity of the kernel 12261e642812SIngo Molnar and slows down exception handling a tiny bit. 12275aef51c3SAndy Lutomirski 12281e642812SIngo Molnar If unsure, say N here. 12295aef51c3SAndy Lutomirski 12305aef51c3SAndy Lutomirskiconfig VM86 12315aef51c3SAndy Lutomirski bool 12325aef51c3SAndy Lutomirski default X86_LEGACY_VM86 123334273f41SH. Peter Anvin 123434273f41SH. Peter Anvinconfig X86_16BIT 123534273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 123634273f41SH. Peter Anvin default y 1237a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1238a7f7f624SMasahiro Yamada help 123934273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 124034273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 124134273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 124234273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 124334273f41SH. Peter Anvin 124434273f41SH. Peter Anvinconfig X86_ESPFIX32 124534273f41SH. Peter Anvin def_bool y 124634273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1247506f1d07SSam Ravnborg 1248197725deSH. Peter Anvinconfig X86_ESPFIX64 1249197725deSH. Peter Anvin def_bool y 125034273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1251506f1d07SSam Ravnborg 12521ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12531ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12541ad83c85SAndy Lutomirski default y 12551ad83c85SAndy Lutomirski depends on X86_64 1256a7f7f624SMasahiro Yamada help 12571ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12581ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12591ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12601ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12611ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12621ad83c85SAndy Lutomirski 0xffffffffff600?00. 12631ad83c85SAndy Lutomirski 12641ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12651ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12661ad83c85SAndy Lutomirski 12671ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12681ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12691ad83c85SAndy Lutomirski 1270111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1271111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1272a24ca997SThomas Gleixner default y 1273a7f7f624SMasahiro Yamada help 1274111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1275111e7b15SThomas Gleixner for legacy applications. 1276111e7b15SThomas Gleixner 1277c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1278c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1279c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1280c8137aceSThomas Gleixner capabilities and permission from potentially active security 1281c8137aceSThomas Gleixner modules. 1282c8137aceSThomas Gleixner 1283c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1284c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1285a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1286a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1287c8137aceSThomas Gleixner 1288506f1d07SSam Ravnborgconfig TOSHIBA 1289506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1290506f1d07SSam Ravnborg depends on X86_32 1291a7f7f624SMasahiro Yamada help 1292506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1293506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1294506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1295506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1296506f1d07SSam Ravnborg 1297506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1298506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1299506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1300506f1d07SSam Ravnborg 1301506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1302506f1d07SSam Ravnborg Say N otherwise. 1303506f1d07SSam Ravnborg 1304506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 13059ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 13069ba16087SJan Beulich depends on X86_32 1307a7f7f624SMasahiro Yamada help 1308506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1309506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1310506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1311506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1312506f1d07SSam Ravnborg system. 1313506f1d07SSam Ravnborg 1314506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 13155e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1316506f1d07SSam Ravnborg 1317506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1318506f1d07SSam Ravnborg enable this option even if you don't need it. 1319506f1d07SSam Ravnborg Say N otherwise. 1320506f1d07SSam Ravnborg 1321506f1d07SSam Ravnborgconfig MICROCODE 13229a2bc335SBorislav Petkov bool "CPU microcode loading support" 13239a2bc335SBorislav Petkov default y 132480030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1325a7f7f624SMasahiro Yamada help 1326506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 13275f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 13285f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 13295f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 13305f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 13315f9c01aaSBorislav Petkov the Linux kernel. 1332506f1d07SSam Ravnborg 13335f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 1334cb1aaebeSMauro Carvalho Chehab in Documentation/x86/microcode.rst. For that you need to enable 13355f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 13365f9c01aaSBorislav Petkov initrd for microcode blobs. 1337506f1d07SSam Ravnborg 1338c508c46eSBenjamin Gilbert In addition, you can build the microcode into the kernel. For that you 1339c508c46eSBenjamin Gilbert need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1340c508c46eSBenjamin Gilbert config option. 1341506f1d07SSam Ravnborg 13428d86f390SPeter Orubaconfig MICROCODE_INTEL 1343e43f6e67SBorislav Petkov bool "Intel microcode loading support" 13449c55d99eSBorislav Petkov depends on CPU_SUP_INTEL && MICROCODE 13458d86f390SPeter Oruba default MICROCODE 1346a7f7f624SMasahiro Yamada help 13478d86f390SPeter Oruba This options enables microcode patch loading support for Intel 13488d86f390SPeter Oruba processors. 13498d86f390SPeter Oruba 1350b8989db9SAlan For the current Intel microcode data package go to 1351b8989db9SAlan <https://downloadcenter.intel.com> and search for 1352b8989db9SAlan 'Linux Processor Microcode Data File'. 13538d86f390SPeter Oruba 135480cc9f10SPeter Orubaconfig MICROCODE_AMD 1355e43f6e67SBorislav Petkov bool "AMD microcode loading support" 13569c55d99eSBorislav Petkov depends on CPU_SUP_AMD && MICROCODE 1357a7f7f624SMasahiro Yamada help 135880cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 135980cc9f10SPeter Oruba processors will be enabled. 136080cc9f10SPeter Oruba 1361a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING 1362a77a94f8SBorislav Petkov bool "Late microcode loading (DANGEROUS)" 1363c02f48e0SBorislav Petkov default n 1364506f1d07SSam Ravnborg depends on MICROCODE 1365a7f7f624SMasahiro Yamada help 1366a77a94f8SBorislav Petkov Loading microcode late, when the system is up and executing instructions 1367a77a94f8SBorislav Petkov is a tricky business and should be avoided if possible. Just the sequence 1368a77a94f8SBorislav Petkov of synchronizing all cores and SMT threads is one fragile dance which does 1369a77a94f8SBorislav Petkov not guarantee that cores might not softlock after the loading. Therefore, 1370a77a94f8SBorislav Petkov use this at your own risk. Late loading taints the kernel too. 1371506f1d07SSam Ravnborg 1372506f1d07SSam Ravnborgconfig X86_MSR 1373506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1374a7f7f624SMasahiro Yamada help 1375506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1376506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1377506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1378506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1379506f1d07SSam Ravnborg systems. 1380506f1d07SSam Ravnborg 1381506f1d07SSam Ravnborgconfig X86_CPUID 1382506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1383a7f7f624SMasahiro Yamada help 1384506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1385506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1386506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1387506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1388506f1d07SSam Ravnborg 1389506f1d07SSam Ravnborgchoice 1390506f1d07SSam Ravnborg prompt "High Memory Support" 13916fc108a0SJan Beulich default HIGHMEM4G 1392506f1d07SSam Ravnborg depends on X86_32 1393506f1d07SSam Ravnborg 1394506f1d07SSam Ravnborgconfig NOHIGHMEM 1395506f1d07SSam Ravnborg bool "off" 1396a7f7f624SMasahiro Yamada help 1397506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1398506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1399506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1400506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1401506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1402506f1d07SSam Ravnborg "high memory". 1403506f1d07SSam Ravnborg 1404506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1405506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1406506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1407506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1408506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1409506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1410506f1d07SSam Ravnborg possible. 1411506f1d07SSam Ravnborg 1412506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1413506f1d07SSam Ravnborg answer "4GB" here. 1414506f1d07SSam Ravnborg 1415506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1416506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1417506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1418506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1419506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1420506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1421506f1d07SSam Ravnborg 1422506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1423506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1424506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1425506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1426506f1d07SSam Ravnborg kernel at boot time.) 1427506f1d07SSam Ravnborg 1428506f1d07SSam Ravnborg If unsure, say "off". 1429506f1d07SSam Ravnborg 1430506f1d07SSam Ravnborgconfig HIGHMEM4G 1431506f1d07SSam Ravnborg bool "4GB" 1432a7f7f624SMasahiro Yamada help 1433506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1434506f1d07SSam Ravnborg gigabytes of physical RAM. 1435506f1d07SSam Ravnborg 1436506f1d07SSam Ravnborgconfig HIGHMEM64G 1437506f1d07SSam Ravnborg bool "64GB" 1438225bac2dSLukas Bulwahn depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 1439506f1d07SSam Ravnborg select X86_PAE 1440a7f7f624SMasahiro Yamada help 1441506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1442506f1d07SSam Ravnborg gigabytes of physical RAM. 1443506f1d07SSam Ravnborg 1444506f1d07SSam Ravnborgendchoice 1445506f1d07SSam Ravnborg 1446506f1d07SSam Ravnborgchoice 14476a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1448506f1d07SSam Ravnborg default VMSPLIT_3G 1449506f1d07SSam Ravnborg depends on X86_32 1450a7f7f624SMasahiro Yamada help 1451506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1452506f1d07SSam Ravnborg 1453506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1454506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1455506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1456506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1457506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1458506f1d07SSam Ravnborg available to user programs, making the address space there 1459506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1460506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1461506f1d07SSam Ravnborg kernel modules. 1462506f1d07SSam Ravnborg 1463506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1464506f1d07SSam Ravnborg option alone! 1465506f1d07SSam Ravnborg 1466506f1d07SSam Ravnborg config VMSPLIT_3G 1467506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1468506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1469506f1d07SSam Ravnborg depends on !X86_PAE 1470506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1471506f1d07SSam Ravnborg config VMSPLIT_2G 1472506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1473506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1474506f1d07SSam Ravnborg depends on !X86_PAE 1475506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1476506f1d07SSam Ravnborg config VMSPLIT_1G 1477506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1478506f1d07SSam Ravnborgendchoice 1479506f1d07SSam Ravnborg 1480506f1d07SSam Ravnborgconfig PAGE_OFFSET 1481506f1d07SSam Ravnborg hex 1482506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1483506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1484506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1485506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1486506f1d07SSam Ravnborg default 0xC0000000 1487506f1d07SSam Ravnborg depends on X86_32 1488506f1d07SSam Ravnborg 1489506f1d07SSam Ravnborgconfig HIGHMEM 14903c2362e6SHarvey Harrison def_bool y 1491506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1492506f1d07SSam Ravnborg 1493506f1d07SSam Ravnborgconfig X86_PAE 14949ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1495506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1496d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14979d99c712SChristian Melki select SWIOTLB 1498a7f7f624SMasahiro Yamada help 1499506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1500506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1501506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1502506f1d07SSam Ravnborg consumes more pagetable space per process. 1503506f1d07SSam Ravnborg 150477ef56e4SKirill A. Shutemovconfig X86_5LEVEL 150577ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 150618ec1eafSKirill A. Shutemov default y 1507eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1508162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 150977ef56e4SKirill A. Shutemov depends on X86_64 1510a7f7f624SMasahiro Yamada help 151177ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 151277ef56e4SKirill A. Shutemov upto 128 PiB of virtual address space and 4 PiB of 151377ef56e4SKirill A. Shutemov physical address space. 151477ef56e4SKirill A. Shutemov 151577ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 151677ef56e4SKirill A. Shutemov 15176657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 15186657fca0SKirill A. Shutemov support 4- or 5-level paging. 151977ef56e4SKirill A. Shutemov 1520cb1aaebeSMauro Carvalho Chehab See Documentation/x86/x86_64/5level-paging.rst for more 152177ef56e4SKirill A. Shutemov information. 152277ef56e4SKirill A. Shutemov 152377ef56e4SKirill A. Shutemov Say N if unsure. 152477ef56e4SKirill A. Shutemov 152510971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1526e5008abeSLuis R. Rodriguez def_bool y 15272e1da13fSVlastimil Babka depends on X86_64 1528a7f7f624SMasahiro Yamada help 152910971ab2SIngo Molnar Certain kernel features effectively disable kernel 153010971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 153110971ab2SIngo Molnar supports them), so don't confuse the user by printing 153210971ab2SIngo Molnar that we have them enabled. 15339e899816SNick Piggin 15345c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15355c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15365c280cf6SThomas Gleixner depends on DEBUG_FS 1537a7f7f624SMasahiro Yamada help 1538b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1539a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15405c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15415c280cf6SThomas Gleixner 154220f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT 154320f07a04SKirill A. Shutemov select ARCH_HAS_FORCE_DMA_UNENCRYPTED 154420f07a04SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 154520f07a04SKirill A. Shutemov def_bool n 154620f07a04SKirill A. Shutemov 15477744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15487744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15497744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 155082fef0adSDavid Rientjes select DMA_COHERENT_POOL 1551ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 1552597cfe48SJoerg Roedel select INSTRUCTION_DECODER 1553aa5a4611STom Lendacky select ARCH_HAS_CC_PLATFORM 155420f07a04SKirill A. Shutemov select X86_MEM_ENCRYPT 1555a7f7f624SMasahiro Yamada help 15567744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15577744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15587744ccdbSTom Lendacky Encryption (SME). 15597744ccdbSTom Lendacky 15607744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15617744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15627744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1563a7f7f624SMasahiro Yamada help 15647744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15657744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15667744ccdbSTom Lendacky 15677744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15687744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15697744ccdbSTom Lendacky 15707744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15717744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15727744ccdbSTom Lendacky 1573506f1d07SSam Ravnborg# Common NUMA Features 1574506f1d07SSam Ravnborgconfig NUMA 1575e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1576506f1d07SSam Ravnborg depends on SMP 1577b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1578b5660ba7SH. Peter Anvin default y if X86_BIGSMP 15797ecd19cfSKefeng Wang select USE_PERCPU_NUMA_NODE_ID 1580a7f7f624SMasahiro Yamada help 1581e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1582fd51b2d7SKOSAKI Motohiro 1583506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1584506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1585506f1d07SSam Ravnborg NUMA awareness to the kernel. 1586506f1d07SSam Ravnborg 1587c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1588fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1589fd51b2d7SKOSAKI Motohiro 1590b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15917cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1592fd51b2d7SKOSAKI Motohiro 1593fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1594506f1d07SSam Ravnborg 1595eec1d4faSHans Rosenfeldconfig AMD_NUMA 15963c2362e6SHarvey Harrison def_bool y 15973c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15985da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1599a7f7f624SMasahiro Yamada help 1600eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1601eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1602eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1603eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1604eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1605506f1d07SSam Ravnborg 1606506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 16073c2362e6SHarvey Harrison def_bool y 16083c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1609506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1610506f1d07SSam Ravnborg select ACPI_NUMA 1611a7f7f624SMasahiro Yamada help 1612506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1613506f1d07SSam Ravnborg 1614506f1d07SSam Ravnborgconfig NUMA_EMU 1615506f1d07SSam Ravnborg bool "NUMA emulation" 16161b7e03efSTejun Heo depends on NUMA 1617a7f7f624SMasahiro Yamada help 1618506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1619506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1620506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1621506f1d07SSam Ravnborg 1622506f1d07SSam Ravnborgconfig NODES_SHIFT 1623d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 162451591e31SDavid Rientjes range 1 10 162551591e31SDavid Rientjes default "10" if MAXSMP 1626506f1d07SSam Ravnborg default "6" if X86_64 1627506f1d07SSam Ravnborg default "3" 1628a9ee6cf5SMike Rapoport depends on NUMA 1629a7f7f624SMasahiro Yamada help 16301184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1631692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1632506f1d07SSam Ravnborg 1633506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1634506f1d07SSam Ravnborg def_bool y 16353b16651fSTejun Heo depends on X86_32 && !NUMA 1636506f1d07SSam Ravnborg 1637506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1638506f1d07SSam Ravnborg def_bool y 16396ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1640506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1641506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1642506f1d07SSam Ravnborg 16433b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16446ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16453b16651fSTejun Heo 1646506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1647506f1d07SSam Ravnborg def_bool y 16484eda2bc3SDavid Hildenbrand depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE 1649506f1d07SSam Ravnborg 1650506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1651a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16525c11f00bSDavid Hildenbrand depends on MEMORY_HOTPLUG 1653a0842b70SToshi Kani help 1654a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1655cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1656a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1657506f1d07SSam Ravnborg 16583b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16593b16651fSTejun Heo def_bool y 16603b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16613b16651fSTejun Heo 1662a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1663a29815a3SAvi Kivity hex 1664a29815a3SAvi Kivity default 0 if X86_32 1665a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1666a29815a3SAvi Kivity 16677a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16687a67832cSDan Williams bool 16697a67832cSDan Williams 1670ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16717a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16729f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16739f53f9faSDan Williams depends on BLK_DEV 16747a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16757b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16769f53f9faSDan Williams select LIBNVDIMM 1677ec776ef6SChristoph Hellwig help 1678ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1679ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1680ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1681ec776ef6SChristoph Hellwig they can be used for persistent storage. 1682ec776ef6SChristoph Hellwig 1683ec776ef6SChristoph Hellwig Say Y if unsure. 1684ec776ef6SChristoph Hellwig 1685506f1d07SSam Ravnborgconfig HIGHPTE 1686506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16876fc108a0SJan Beulich depends on HIGHMEM 1688a7f7f624SMasahiro Yamada help 1689506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1690506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1691506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1692506f1d07SSam Ravnborg entries in high memory. 1693506f1d07SSam Ravnborg 16949f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16959f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1696a7f7f624SMasahiro Yamada help 16979f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16989f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16999f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 17009f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 17019f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 17029f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 17039f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 17048c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 17059f077871SJeremy Fitzhardinge 17069f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 17079f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 17089f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 17099f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 17109f077871SJeremy Fitzhardinge 17119f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 17129f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 17139f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 17149f077871SJeremy Fitzhardinge memory. 17159f077871SJeremy Fitzhardinge 1716c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1717c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1718c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1719c885df50SJeremy Fitzhardinge default y 1720a7f7f624SMasahiro Yamada help 1721c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1722c885df50SJeremy Fitzhardinge on or off. 1723c885df50SJeremy Fitzhardinge 1724506f1d07SSam Ravnborgconfig MATH_EMULATION 1725506f1d07SSam Ravnborg bool 1726a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 172787d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1728a7f7f624SMasahiro Yamada help 1729506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1730506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1731506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1732506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1733506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1734506f1d07SSam Ravnborg coprocessor or this emulation. 1735506f1d07SSam Ravnborg 1736506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1737506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1738506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1739506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1740506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1741506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1742506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1743506f1d07SSam Ravnborg intend to use this kernel on different machines. 1744506f1d07SSam Ravnborg 1745506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1746506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1747506f1d07SSam Ravnborg 1748506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1749506f1d07SSam Ravnborg kernel, it won't hurt. 1750506f1d07SSam Ravnborg 1751506f1d07SSam Ravnborgconfig MTRR 17526fc108a0SJan Beulich def_bool y 17536a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1754a7f7f624SMasahiro Yamada help 1755506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1756506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1757506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1758506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1759506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1760506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1761506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1762506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1763506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1764506f1d07SSam Ravnborg 1765506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1766506f1d07SSam Ravnborg control registers on other processors can be easily supported 1767506f1d07SSam Ravnborg as well: 1768506f1d07SSam Ravnborg 1769506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1770506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1771506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1772506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1773506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1774506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1775506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1776506f1d07SSam Ravnborg 1777506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1778506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1779506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1780506f1d07SSam Ravnborg 1781506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1782506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1783506f1d07SSam Ravnborg 1784cb1aaebeSMauro Carvalho Chehab See <file:Documentation/x86/mtrr.rst> for more information. 1785506f1d07SSam Ravnborg 178695ffa243SYinghai Luconfig MTRR_SANITIZER 17872ffb3501SYinghai Lu def_bool y 178895ffa243SYinghai Lu prompt "MTRR cleanup support" 178995ffa243SYinghai Lu depends on MTRR 1790a7f7f624SMasahiro Yamada help 1791aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1792aba3728cSThomas Gleixner add writeback entries. 179395ffa243SYinghai Lu 1794aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1795692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1796aba3728cSThomas Gleixner mtrr_chunk_size. 179795ffa243SYinghai Lu 17982ffb3501SYinghai Lu If unsure, say Y. 179995ffa243SYinghai Lu 180095ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1801f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1802f5098d62SYinghai Lu range 0 1 1803f5098d62SYinghai Lu default "0" 180495ffa243SYinghai Lu depends on MTRR_SANITIZER 1805a7f7f624SMasahiro Yamada help 1806f5098d62SYinghai Lu Enable mtrr cleanup default value 180795ffa243SYinghai Lu 180812031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 180912031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 181012031a62SYinghai Lu range 0 7 181112031a62SYinghai Lu default "1" 181212031a62SYinghai Lu depends on MTRR_SANITIZER 1813a7f7f624SMasahiro Yamada help 181412031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1815aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 181612031a62SYinghai Lu 18172e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 18186fc108a0SJan Beulich def_bool y 18196a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 18202a8a2719SIngo Molnar depends on MTRR 1821a7f7f624SMasahiro Yamada help 18222e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1823042b78e4SVenki Pallipadi 18242e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 18252e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 18262e5d9c85Svenkatesh.pallipadi@intel.com 18272e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1828042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 18292e5d9c85Svenkatesh.pallipadi@intel.com 18302e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 18312e5d9c85Svenkatesh.pallipadi@intel.com 183246cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 183346cf98cdSVenkatesh Pallipadi def_bool y 183446cf98cdSVenkatesh Pallipadi depends on X86_PAT 183546cf98cdSVenkatesh Pallipadi 1836628c6246SH. Peter Anvinconfig ARCH_RANDOM 1837628c6246SH. Peter Anvin def_bool y 1838628c6246SH. Peter Anvin prompt "x86 architectural random number generator" if EXPERT 1839a7f7f624SMasahiro Yamada help 1840628c6246SH. Peter Anvin Enable the x86 architectural RDRAND instruction 1841628c6246SH. Peter Anvin (Intel Bull Mountain technology) to generate random numbers. 1842628c6246SH. Peter Anvin If supported, this is a high bandwidth, cryptographically 1843628c6246SH. Peter Anvin secure hardware random number generator. 1844628c6246SH. Peter Anvin 1845b971880fSBabu Mogerconfig X86_UMIP 1846796ebc81SRicardo Neri def_bool y 1847b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1848a7f7f624SMasahiro Yamada help 1849b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1850b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1851b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1852b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1853b971880fSBabu Moger information about the hardware state. 1854796ebc81SRicardo Neri 1855796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1856796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1857796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1858796ebc81SRicardo Neri results are dummy. 1859aa35f896SRicardo Neri 1860156ff4a5SPeter Zijlstraconfig CC_HAS_IBT 1861156ff4a5SPeter Zijlstra # GCC >= 9 and binutils >= 2.29 1862156ff4a5SPeter Zijlstra # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 1863156ff4a5SPeter Zijlstra # Clang/LLVM >= 14 1864262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f 1865262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 1866156ff4a5SPeter Zijlstra def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ 1867262448f3SNathan Chancellor (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ 1868156ff4a5SPeter Zijlstra $(as-instr,endbr64) 1869156ff4a5SPeter Zijlstra 1870156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT 1871156ff4a5SPeter Zijlstra prompt "Indirect Branch Tracking" 1872156ff4a5SPeter Zijlstra bool 187303f16cd0SJosh Poimboeuf depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL 1874f6a2c2b2SNathan Chancellor # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f 1875f6a2c2b2SNathan Chancellor depends on !LD_IS_LLD || LLD_VERSION >= 140000 187603f16cd0SJosh Poimboeuf select OBJTOOL 1877156ff4a5SPeter Zijlstra help 1878156ff4a5SPeter Zijlstra Build the kernel with support for Indirect Branch Tracking, a 1879156ff4a5SPeter Zijlstra hardware support course-grain forward-edge Control Flow Integrity 1880156ff4a5SPeter Zijlstra protection. It enforces that all indirect calls must land on 1881156ff4a5SPeter Zijlstra an ENDBR instruction, as such, the compiler will instrument the 1882156ff4a5SPeter Zijlstra code with them to make this happen. 1883156ff4a5SPeter Zijlstra 1884ed53a0d9SPeter Zijlstra In addition to building the kernel with IBT, seal all functions that 18854cdfc11bSNur Hussein are not indirect call targets, avoiding them ever becoming one. 1886ed53a0d9SPeter Zijlstra 1887ed53a0d9SPeter Zijlstra This requires LTO like objtool runs and will slow down the build. It 1888ed53a0d9SPeter Zijlstra does significantly reduce the number of ENDBR instructions in the 1889ed53a0d9SPeter Zijlstra kernel image. 1890ed53a0d9SPeter Zijlstra 189135e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 189238f3e775SBabu Moger prompt "Memory Protection Keys" 189335e97790SDave Hansen def_bool y 1894284244a9SDave Hansen # Note: only available in 64-bit mode 189538f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 189652c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 189752c8e601SIngo Molnar select ARCH_HAS_PKEYS 1898a7f7f624SMasahiro Yamada help 1899284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1900284244a9SDave Hansen page-based protections, but without requiring modification of the 1901284244a9SDave Hansen page tables when an application changes protection domains. 1902284244a9SDave Hansen 19031eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1904284244a9SDave Hansen 1905284244a9SDave Hansen If unsure, say y. 190635e97790SDave Hansen 1907db616173SMichal Hockochoice 1908db616173SMichal Hocko prompt "TSX enable mode" 1909db616173SMichal Hocko depends on CPU_SUP_INTEL 1910db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1911db616173SMichal Hocko help 1912db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1913db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1914db616173SMichal Hocko can lead to a noticeable performance boost. 1915db616173SMichal Hocko 1916db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1917db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1918db616173SMichal Hocko will be more of those attacks discovered in the future. 1919db616173SMichal Hocko 1920db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1921db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1922db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1923db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1924db616173SMichal Hocko for the particular machine. 1925db616173SMichal Hocko 1926db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1927db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1928db616173SMichal Hocko details. 1929db616173SMichal Hocko 1930db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1931db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1932db616173SMichal Hocko relevant. 1933db616173SMichal Hocko 1934db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1935db616173SMichal Hocko bool "off" 1936db616173SMichal Hocko help 1937db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1938db616173SMichal Hocko 1939db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1940db616173SMichal Hocko bool "on" 1941db616173SMichal Hocko help 1942db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1943db616173SMichal Hocko line parameter. 1944db616173SMichal Hocko 1945db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1946db616173SMichal Hocko bool "auto" 1947db616173SMichal Hocko help 1948db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1949db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1950db616173SMichal Hockoendchoice 1951db616173SMichal Hocko 1952e7e05452SSean Christophersonconfig X86_SGX 1953e7e05452SSean Christopherson bool "Software Guard eXtensions (SGX)" 1954e7e05452SSean Christopherson depends on X86_64 && CPU_SUP_INTEL 1955e7e05452SSean Christopherson depends on CRYPTO=y 1956e7e05452SSean Christopherson depends on CRYPTO_SHA256=y 1957e7e05452SSean Christopherson select SRCU 1958e7e05452SSean Christopherson select MMU_NOTIFIER 1959901ddbb9SJarkko Sakkinen select NUMA_KEEP_MEMINFO if NUMA 196040e0e784STony Luck select XARRAY_MULTI 1961e7e05452SSean Christopherson help 1962e7e05452SSean Christopherson Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1963e7e05452SSean Christopherson that can be used by applications to set aside private regions of code 1964e7e05452SSean Christopherson and data, referred to as enclaves. An enclave's private memory can 1965e7e05452SSean Christopherson only be accessed by code running within the enclave. Accesses from 1966e7e05452SSean Christopherson outside the enclave, including other enclaves, are disallowed by 1967e7e05452SSean Christopherson hardware. 1968e7e05452SSean Christopherson 1969e7e05452SSean Christopherson If unsure, say N. 1970e7e05452SSean Christopherson 1971506f1d07SSam Ravnborgconfig EFI 19729ba16087SJan Beulich bool "EFI runtime service support" 19735b83683fSHuang, Ying depends on ACPI 1974f6ce5002SSergey Vlasov select UCS2_STRING 1975022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 19761ff2fc02STom Lendacky select ARCH_USE_MEMREMAP_PROT 1977a7f7f624SMasahiro Yamada help 19788b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1979506f1d07SSam Ravnborg available (such as the EFI variable services). 1980506f1d07SSam Ravnborg 19818b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19828b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19838b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19848b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19858b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19868b2cb7a8SHuang, Ying platforms. 1987506f1d07SSam Ravnborg 1988291f3632SMatt Flemingconfig EFI_STUB 1989291f3632SMatt Fleming bool "EFI stub support" 1990c6dbd3e5SPeter Zijlstra depends on EFI 19918f24f8c2SArd Biesheuvel depends on $(cc-option,-mabi=ms) || X86_32 19927b2a583aSMatt Fleming select RELOCATABLE 1993a7f7f624SMasahiro Yamada help 1994291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1995291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1996291f3632SMatt Fleming 19974f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19980c759662SMatt Fleming 19997d453eeeSMatt Flemingconfig EFI_MIXED 20007d453eeeSMatt Fleming bool "EFI mixed-mode support" 20017d453eeeSMatt Fleming depends on EFI_STUB && X86_64 2002a7f7f624SMasahiro Yamada help 20037d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 20047d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 20057d453eeeSMatt Fleming mode. 20067d453eeeSMatt Fleming 20077d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 20087d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 20097d453eeeSMatt Fleming the EFI handover protocol must be used. 20107d453eeeSMatt Fleming 20117d453eeeSMatt Fleming If unsure, say N. 20127d453eeeSMatt Fleming 20138636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 2014506f1d07SSam Ravnborg 2015506f1d07SSam Ravnborgconfig KEXEC 2016506f1d07SSam Ravnborg bool "kexec system call" 20172965faa5SDave Young select KEXEC_CORE 2018a7f7f624SMasahiro Yamada help 2019506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 2020506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 2021506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 2022506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 2023506f1d07SSam Ravnborg 2024506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 2025506f1d07SSam Ravnborg 2026506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 2027506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 2028bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 2029bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 2030bf220695SGeert Uytterhoeven made. 2031506f1d07SSam Ravnborg 203274ca317cSVivek Goyalconfig KEXEC_FILE 203374ca317cSVivek Goyal bool "kexec file based system call" 20342965faa5SDave Young select KEXEC_CORE 203574ca317cSVivek Goyal select BUILD_BIN2C 203674ca317cSVivek Goyal depends on X86_64 203774ca317cSVivek Goyal depends on CRYPTO=y 203874ca317cSVivek Goyal depends on CRYPTO_SHA256=y 2039a7f7f624SMasahiro Yamada help 204074ca317cSVivek Goyal This is new version of kexec system call. This system call is 204174ca317cSVivek Goyal file based and takes file descriptors as system call argument 204274ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 204374ca317cSVivek Goyal accepted by previous system call. 204474ca317cSVivek Goyal 2045b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY 2046b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 2047b799a09fSAKASHI Takahiro 204899d5cadfSJiri Bohacconfig KEXEC_SIG 20498e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 205074ca317cSVivek Goyal depends on KEXEC_FILE 2051a7f7f624SMasahiro Yamada help 205299d5cadfSJiri Bohac 205399d5cadfSJiri Bohac This option makes the kexec_file_load() syscall check for a valid 205499d5cadfSJiri Bohac signature of the kernel image. The image can still be loaded without 205599d5cadfSJiri Bohac a valid signature unless you also enable KEXEC_SIG_FORCE, though if 205699d5cadfSJiri Bohac there's a signature that we can check, then it must be valid. 205799d5cadfSJiri Bohac 205899d5cadfSJiri Bohac In addition to this option, you need to enable signature 205999d5cadfSJiri Bohac verification for the corresponding kernel image type being 206099d5cadfSJiri Bohac loaded in order for this to work. 206199d5cadfSJiri Bohac 206299d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE 206399d5cadfSJiri Bohac bool "Require a valid signature in kexec_file_load() syscall" 206499d5cadfSJiri Bohac depends on KEXEC_SIG 2065a7f7f624SMasahiro Yamada help 20668e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 2067d8eb8940SBorislav Petkov the kexec_file_load() syscall. 20688e7d8381SVivek Goyal 20698e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 20708e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 207199d5cadfSJiri Bohac depends on KEXEC_SIG 20728e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 20738e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 2074a7f7f624SMasahiro Yamada help 20758e7d8381SVivek Goyal Enable bzImage signature verification support. 20768e7d8381SVivek Goyal 2077506f1d07SSam Ravnborgconfig CRASH_DUMP 207804b69447SPavel Machek bool "kernel crash dumps" 2079506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2080a7f7f624SMasahiro Yamada help 2081506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 2082506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 2083506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 2084506f1d07SSam Ravnborg a specially reserved region and then later executed after 2085506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 2086506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 2087506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 2088506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 2089330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 2090506f1d07SSam Ravnborg 20913ab83521SHuang Yingconfig KEXEC_JUMP 20926ea30386SKees Cook bool "kexec jump" 2093fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 2094a7f7f624SMasahiro Yamada help 209589081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 209689081d17SHuang Ying code in physical address mode via KEXEC 20973ab83521SHuang Ying 2098506f1d07SSam Ravnborgconfig PHYSICAL_START 20996a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2100ceefccc9SH. Peter Anvin default "0x1000000" 2101a7f7f624SMasahiro Yamada help 2102506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2103506f1d07SSam Ravnborg 2104506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2105506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2106506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2107506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2108506f1d07SSam Ravnborg address. 2109506f1d07SSam Ravnborg 2110506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2111506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2112506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2113506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2114506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2115506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2116506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2117506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2118506f1d07SSam Ravnborg 2119ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2120ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2121ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2122ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2123ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2124ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2125ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2126330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2127ceefccc9SH. Peter Anvin for more details about crash dumps. 2128506f1d07SSam Ravnborg 2129506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2130506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2131506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2132506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2133506f1d07SSam Ravnborg is present because there are users out there who continue to use 2134506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2135506f1d07SSam Ravnborg line. 2136506f1d07SSam Ravnborg 2137506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2138506f1d07SSam Ravnborg 2139506f1d07SSam Ravnborgconfig RELOCATABLE 214026717808SH. Peter Anvin bool "Build a relocatable kernel" 214126717808SH. Peter Anvin default y 2142a7f7f624SMasahiro Yamada help 2143506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2144506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2145506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2146506f1d07SSam Ravnborg but are discarded at runtime. 2147506f1d07SSam Ravnborg 2148506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2149506f1d07SSam Ravnborg must live at a different physical address than the primary 2150506f1d07SSam Ravnborg kernel. 2151506f1d07SSam Ravnborg 2152506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2153506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21548ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2155506f1d07SSam Ravnborg 21568ab3820fSKees Cookconfig RANDOMIZE_BASE 2157e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21588ab3820fSKees Cook depends on RELOCATABLE 21596807c846SIngo Molnar default y 2160a7f7f624SMasahiro Yamada help 2161e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2162e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2163e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2164e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2165e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2166e8581e3dSBaoquan He code internals. 2167e8581e3dSBaoquan He 2168ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2169ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2170ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2171ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2172ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2173ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2174ed9f007eSKees Cook 2175ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2176ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2177ed9f007eSKees Cook 512MB (8 bits of entropy). 21788ab3820fSKees Cook 2179a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2180e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2181e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2182ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2183ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2184ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2185ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2186ed9f007eSKees Cook theoretically possible, but the implementations are further 2187ed9f007eSKees Cook limited due to memory layouts. 2188e8581e3dSBaoquan He 21896807c846SIngo Molnar If unsure, say Y. 2190da2b6fb9SKees Cook 21918ab3820fSKees Cook# Relocation on x86 needs some additional build support 2192845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2193845adf72SH. Peter Anvin def_bool y 21948ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2195845adf72SH. Peter Anvin 2196506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2197a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 21988ab3820fSKees Cook default "0x200000" 2199a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2200a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2201a7f7f624SMasahiro Yamada help 2202506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2203506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2204506f1d07SSam Ravnborg address which meets above alignment restriction. 2205506f1d07SSam Ravnborg 2206506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2207506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2208506f1d07SSam Ravnborg address aligned to above value and run from there. 2209506f1d07SSam Ravnborg 2210506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2211506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2212506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2213506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2214506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2215506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2216506f1d07SSam Ravnborg above alignment restrictions. 2217506f1d07SSam Ravnborg 2218a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2219a0215061SKees Cook this value must be a multiple of 0x200000. 2220a0215061SKees Cook 2221506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2222506f1d07SSam Ravnborg 2223eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2224eedb92abSKirill A. Shutemov bool 2225a7f7f624SMasahiro Yamada help 2226eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2227eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2228eedb92abSKirill A. Shutemov 22290483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 22300483e1faSThomas Garnier bool "Randomize the kernel memory sections" 22310483e1faSThomas Garnier depends on X86_64 22320483e1faSThomas Garnier depends on RANDOMIZE_BASE 2233eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 22340483e1faSThomas Garnier default RANDOMIZE_BASE 2235a7f7f624SMasahiro Yamada help 22360483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 22370483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 22380483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 22390483e1faSThomas Garnier 22400483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 22410483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 22420483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 22430483e1faSThomas Garnier addresses for each memory section. 22440483e1faSThomas Garnier 22456807c846SIngo Molnar If unsure, say Y. 22460483e1faSThomas Garnier 224790397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 224890397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 224990397a41SThomas Garnier depends on RANDOMIZE_MEMORY 225090397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 225190397a41SThomas Garnier default "0x0" 225290397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 225390397a41SThomas Garnier range 0x0 0x40 2254a7f7f624SMasahiro Yamada help 225590397a41SThomas Garnier Define the padding in terabytes added to the existing physical 225690397a41SThomas Garnier memory size during kernel memory randomization. It is useful 225790397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 225890397a41SThomas Garnier address randomization. 225990397a41SThomas Garnier 226090397a41SThomas Garnier If unsure, leave at the default value. 226190397a41SThomas Garnier 2262506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2263bebd024eSThomas Gleixner def_bool y 226440b31360SStephen Rothwell depends on SMP 2265506f1d07SSam Ravnborg 226680aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0 226780aa1dffSFenghua Yu bool "Set default setting of cpu0_hotpluggable" 22682c922cd0SKees Cook depends on HOTPLUG_CPU 2269a7f7f624SMasahiro Yamada help 227080aa1dffSFenghua Yu Set whether default state of cpu0_hotpluggable is on or off. 227180aa1dffSFenghua Yu 227280aa1dffSFenghua Yu Say Y here to enable CPU0 hotplug by default. If this switch 227380aa1dffSFenghua Yu is turned on, there is no need to give cpu0_hotplug kernel 227480aa1dffSFenghua Yu parameter and the CPU0 hotplug feature is enabled by default. 227580aa1dffSFenghua Yu 227680aa1dffSFenghua Yu Please note: there are two known CPU0 dependencies if you want 227780aa1dffSFenghua Yu to enable the CPU0 hotplug feature either by this switch or by 227880aa1dffSFenghua Yu cpu0_hotplug kernel parameter. 227980aa1dffSFenghua Yu 228080aa1dffSFenghua Yu First, resume from hibernate or suspend always starts from CPU0. 228180aa1dffSFenghua Yu So hibernate and suspend are prevented if CPU0 is offline. 228280aa1dffSFenghua Yu 228380aa1dffSFenghua Yu Second dependency is PIC interrupts always go to CPU0. CPU0 can not 228480aa1dffSFenghua Yu offline if any interrupt can not migrate out of CPU0. There may 228580aa1dffSFenghua Yu be other CPU0 dependencies. 228680aa1dffSFenghua Yu 228780aa1dffSFenghua Yu Please make sure the dependencies are under your control before 228880aa1dffSFenghua Yu you enable this feature. 228980aa1dffSFenghua Yu 229080aa1dffSFenghua Yu Say N if you don't want to enable CPU0 hotplug feature by default. 229180aa1dffSFenghua Yu You still can enable the CPU0 hotplug feature at boot by kernel 229280aa1dffSFenghua Yu parameter cpu0_hotplug. 229380aa1dffSFenghua Yu 2294a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0 2295a71c8bc5SFenghua Yu def_bool n 2296a71c8bc5SFenghua Yu prompt "Debug CPU0 hotplug" 22972c922cd0SKees Cook depends on HOTPLUG_CPU 2298a7f7f624SMasahiro Yamada help 2299a71c8bc5SFenghua Yu Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2300a71c8bc5SFenghua Yu soon as possible and boots up userspace with CPU0 offlined. User 2301a71c8bc5SFenghua Yu can online CPU0 back after boot time. 2302a71c8bc5SFenghua Yu 2303a71c8bc5SFenghua Yu To debug CPU0 hotplug, you need to enable CPU0 offline/online 2304a71c8bc5SFenghua Yu feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2305a71c8bc5SFenghua Yu compilation or giving cpu0_hotplug kernel parameter at boot. 2306a71c8bc5SFenghua Yu 2307a71c8bc5SFenghua Yu If unsure, say N. 2308a71c8bc5SFenghua Yu 2309506f1d07SSam Ravnborgconfig COMPAT_VDSO 2310b0b49f26SAndy Lutomirski def_bool n 2311b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2312953fee1dSIngo Molnar depends on COMPAT_32 2313a7f7f624SMasahiro Yamada help 2314b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2315b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2316b0b49f26SAndy Lutomirski indicated in its segment table. 2317e84446deSRandy Dunlap 2318b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2319b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2320b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2321b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2322b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2323506f1d07SSam Ravnborg 2324b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2325b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2326b0b49f26SAndy Lutomirski 2327b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2328b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2329b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2330b0b49f26SAndy Lutomirski 2331b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2332b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2333506f1d07SSam Ravnborg 23343dc33bd3SKees Cookchoice 23353dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 23363dc33bd3SKees Cook depends on X86_64 2337625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 23383dc33bd3SKees Cook help 23393dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 23403dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 23413dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 23423dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 23433dc33bd3SKees Cook 23443dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2345bf00745eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. Emulate mode 2346bf00745eSAndy Lutomirski is deprecated and can only be enabled using the kernel command 2347bf00745eSAndy Lutomirski line. 23483dc33bd3SKees Cook 23493dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 23503dc33bd3SKees Cook static binaries, you can say None without a performance penalty 23513dc33bd3SKees Cook to improve security. 23523dc33bd3SKees Cook 2353bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 23543dc33bd3SKees Cook 2355bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2356bd49e16eSAndy Lutomirski bool "Emulate execution only" 2357bd49e16eSAndy Lutomirski help 2358bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2359bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2360bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2361bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2362bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2363bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2364bd49e16eSAndy Lutomirski buffer. 23653dc33bd3SKees Cook 23663dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23673dc33bd3SKees Cook bool "None" 23683dc33bd3SKees Cook help 23693dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23703dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23713dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23723dc33bd3SKees Cook will be reported to dmesg, so that either old or 23733dc33bd3SKees Cook malicious userspace programs can be identified. 23743dc33bd3SKees Cook 23753dc33bd3SKees Cookendchoice 23763dc33bd3SKees Cook 2377516cbf37STim Birdconfig CMDLINE_BOOL 2378516cbf37STim Bird bool "Built-in kernel command line" 2379a7f7f624SMasahiro Yamada help 2380516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2381516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2382516cbf37STim Bird necessary or convenient to provide some or all of the 2383516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2384516cbf37STim Bird to not rely on the boot loader to provide them.) 2385516cbf37STim Bird 2386516cbf37STim Bird To compile command line arguments into the kernel, 2387516cbf37STim Bird set this option to 'Y', then fill in the 238869711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2389516cbf37STim Bird 2390516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2391516cbf37STim Bird should leave this option set to 'N'. 2392516cbf37STim Bird 2393516cbf37STim Birdconfig CMDLINE 2394516cbf37STim Bird string "Built-in kernel command string" 2395516cbf37STim Bird depends on CMDLINE_BOOL 2396516cbf37STim Bird default "" 2397a7f7f624SMasahiro Yamada help 2398516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2399516cbf37STim Bird image and used at boot time. If the boot loader provides a 2400516cbf37STim Bird command line at boot time, it is appended to this string to 2401516cbf37STim Bird form the full kernel command line, when the system boots. 2402516cbf37STim Bird 2403516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2404516cbf37STim Bird change this behavior. 2405516cbf37STim Bird 2406516cbf37STim Bird In most cases, the command line (whether built-in or provided 2407516cbf37STim Bird by the boot loader) should specify the device for the root 2408516cbf37STim Bird file system. 2409516cbf37STim Bird 2410516cbf37STim Birdconfig CMDLINE_OVERRIDE 2411516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2412645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2413a7f7f624SMasahiro Yamada help 2414516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2415516cbf37STim Bird command line, and use ONLY the built-in command line. 2416516cbf37STim Bird 2417516cbf37STim Bird This is used to work around broken boot loaders. This should 2418516cbf37STim Bird be set to 'N' under normal conditions. 2419516cbf37STim Bird 2420a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2421a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2422a5b9e5a2SAndy Lutomirski default y 2423a7f7f624SMasahiro Yamada help 2424a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2425a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2426a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2427a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2428a5b9e5a2SAndy Lutomirski threading libraries. 2429a5b9e5a2SAndy Lutomirski 2430a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2431a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2432a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2433a5b9e5a2SAndy Lutomirski 2434a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2435a5b9e5a2SAndy Lutomirski 24363aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE 24373aac3ebeSThomas Gleixner bool "Enforce strict size checking for sigaltstack" 24383aac3ebeSThomas Gleixner depends on DYNAMIC_SIGFRAME 24393aac3ebeSThomas Gleixner help 24403aac3ebeSThomas Gleixner For historical reasons MINSIGSTKSZ is a constant which became 24413aac3ebeSThomas Gleixner already too small with AVX512 support. Add a mechanism to 24423aac3ebeSThomas Gleixner enforce strict checking of the sigaltstack size against the 24433aac3ebeSThomas Gleixner real size of the FPU frame. This option enables the check 24443aac3ebeSThomas Gleixner by default. It can also be controlled via the kernel command 24453aac3ebeSThomas Gleixner line option 'strict_sas_size' independent of this config 24463aac3ebeSThomas Gleixner switch. Enabling it might break existing applications which 24473aac3ebeSThomas Gleixner allocate a too small sigaltstack but 'work' because they 24483aac3ebeSThomas Gleixner never get a signal delivered. 24493aac3ebeSThomas Gleixner 24503aac3ebeSThomas Gleixner Say 'N' unless you want to really enforce this check. 24513aac3ebeSThomas Gleixner 2452b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2453b700e7f0SSeth Jennings 2454506f1d07SSam Ravnborgendmenu 2455506f1d07SSam Ravnborg 24563072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 24573072e413SMichal Hocko def_bool y 24585c11f00bSDavid Hildenbrand depends on ARCH_ENABLE_MEMORY_HOTPLUG 24593072e413SMichal Hocko 2460f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 2461f91ef222SOscar Salvador def_bool y 2462f91ef222SOscar Salvador 2463da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2464e279b6c1SSam Ravnborg 2465e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 24663c2362e6SHarvey Harrison def_bool y 246744556530SZhimin Gu depends on HIBERNATION 2468e279b6c1SSam Ravnborg 2469e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2470e279b6c1SSam Ravnborg 2471e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2472e279b6c1SSam Ravnborg 2473a6b68076SAndi Kleenconfig X86_APM_BOOT 24746fc108a0SJan Beulich def_bool y 2475282e5aabSPaul Bolle depends on APM 2476a6b68076SAndi Kleen 2477e279b6c1SSam Ravnborgmenuconfig APM 2478e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2479efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2480a7f7f624SMasahiro Yamada help 2481e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2482e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2483e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2484e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2485e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2486e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2487e279b6c1SSam Ravnborg 2488e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2489e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2490e279b6c1SSam Ravnborg 2491e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2492e279b6c1SSam Ravnborg machines with more than one CPU. 2493e279b6c1SSam Ravnborg 2494e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2495151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 24962dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2497e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2498e279b6c1SSam Ravnborg 2499e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2500e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2501e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2502e279b6c1SSam Ravnborg 2503e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2504e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2505e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2506e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2507e279b6c1SSam Ravnborg 2508e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2509e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2510e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2511e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2512e279b6c1SSam Ravnborg APM in your BIOS). 2513e279b6c1SSam Ravnborg 2514e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2515e279b6c1SSam Ravnborg "weird" problems: 2516e279b6c1SSam Ravnborg 2517e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2518e279b6c1SSam Ravnborg enabled. 2519e279b6c1SSam Ravnborg 2) pass the "no-hlt" option to the kernel 2520e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2521e279b6c1SSam Ravnborg the "no387" option to the kernel 2522e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2523e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2524e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2525e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2526e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2527e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2528e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2529e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2530e279b6c1SSam Ravnborg 11) exchange RAM chips 2531e279b6c1SSam Ravnborg 12) exchange the motherboard. 2532e279b6c1SSam Ravnborg 2533e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2534e279b6c1SSam Ravnborg module will be called apm. 2535e279b6c1SSam Ravnborg 2536e279b6c1SSam Ravnborgif APM 2537e279b6c1SSam Ravnborg 2538e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2539e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2540a7f7f624SMasahiro Yamada help 2541e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2542e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2543e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2544e279b6c1SSam Ravnborg 2545e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2546e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2547a7f7f624SMasahiro Yamada help 2548e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2549e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2550e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2551e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2552e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2553e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2554e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2555e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2556e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2557e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2558e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2559e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2560e279b6c1SSam Ravnborg this feature. 2561e279b6c1SSam Ravnborg 2562e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2563dd8af076SLen Brown depends on CPU_IDLE 2564e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2565a7f7f624SMasahiro Yamada help 2566e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2567e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2568e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2569e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2570e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2571e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2572e279b6c1SSam Ravnborg this option does nothing.) 2573e279b6c1SSam Ravnborg 2574e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2575e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2576a7f7f624SMasahiro Yamada help 2577e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2578e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2579e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2580e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2581e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2582e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2583e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2584e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2585e279b6c1SSam Ravnborg especially if you are using gpm. 2586e279b6c1SSam Ravnborg 2587e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2588e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2589a7f7f624SMasahiro Yamada help 2590e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2591e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2592e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2593e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2594e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2595e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2596e279b6c1SSam Ravnborg 2597e279b6c1SSam Ravnborgendif # APM 2598e279b6c1SSam Ravnborg 2599bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2600e279b6c1SSam Ravnborg 2601e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2602e279b6c1SSam Ravnborg 260327471fdbSAndy Henroidsource "drivers/idle/Kconfig" 260427471fdbSAndy Henroid 2605e279b6c1SSam Ravnborgendmenu 2606e279b6c1SSam Ravnborg 2607e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2608e279b6c1SSam Ravnborg 2609e279b6c1SSam Ravnborgchoice 2610e279b6c1SSam Ravnborg prompt "PCI access mode" 2611efefa6f6SIngo Molnar depends on X86_32 && PCI 2612e279b6c1SSam Ravnborg default PCI_GOANY 2613a7f7f624SMasahiro Yamada help 2614e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2615e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2616e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2617e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2618e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2619e279b6c1SSam Ravnborg 2620e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2621e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2622e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2623e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2624e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2625e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2626e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2627e279b6c1SSam Ravnborg 2628e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2629e279b6c1SSam Ravnborg bool "BIOS" 2630e279b6c1SSam Ravnborg 2631e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2632e279b6c1SSam Ravnborg bool "MMConfig" 2633e279b6c1SSam Ravnborg 2634e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2635e279b6c1SSam Ravnborg bool "Direct" 2636e279b6c1SSam Ravnborg 26373ef0e1f8SAndres Salomonconfig PCI_GOOLPC 263876fb6570SDaniel Drake bool "OLPC XO-1" 26393ef0e1f8SAndres Salomon depends on OLPC 26403ef0e1f8SAndres Salomon 26412bdd1b03SAndres Salomonconfig PCI_GOANY 26422bdd1b03SAndres Salomon bool "Any" 26432bdd1b03SAndres Salomon 2644e279b6c1SSam Ravnborgendchoice 2645e279b6c1SSam Ravnborg 2646e279b6c1SSam Ravnborgconfig PCI_BIOS 26473c2362e6SHarvey Harrison def_bool y 2648efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2649e279b6c1SSam Ravnborg 2650e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2651e279b6c1SSam Ravnborgconfig PCI_DIRECT 26523c2362e6SHarvey Harrison def_bool y 26530aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2654e279b6c1SSam Ravnborg 2655e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2656b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2657b45c9f36SJan Kiszka default y 26584590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2659b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2660e279b6c1SSam Ravnborg 26613ef0e1f8SAndres Salomonconfig PCI_OLPC 26622bdd1b03SAndres Salomon def_bool y 26632bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 26643ef0e1f8SAndres Salomon 2665b5401a96SAlex Nixonconfig PCI_XEN 2666b5401a96SAlex Nixon def_bool y 2667b5401a96SAlex Nixon depends on PCI && XEN 2668b5401a96SAlex Nixon 26698364e1f8SJan Kiszkaconfig MMCONF_FAM10H 26708364e1f8SJan Kiszka def_bool y 26718364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2672e279b6c1SSam Ravnborg 26733f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 26746a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 26756ea30386SKees Cook depends on PCI 26763f6ea84aSIra W. Snyder help 26773f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 26783f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 26793f6ea84aSIra W. Snyder not have ACPI. 26803f6ea84aSIra W. Snyder 268164a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 268264a5fed6SBjorn Helgaas is known to be incomplete. 268364a5fed6SBjorn Helgaas 268464a5fed6SBjorn Helgaas You should say N unless you know you need this. 268564a5fed6SBjorn Helgaas 26863a495511SWilliam Breathitt Grayconfig ISA_BUS 268717a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 26883a495511SWilliam Breathitt Gray help 268917a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 269017a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 269117a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 269217a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 269317a2a129SWilliam Breathitt Gray not have an ISA bus. 26943a495511SWilliam Breathitt Gray 26953a495511SWilliam Breathitt Gray If unsure, say N. 26963a495511SWilliam Breathitt Gray 26971c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2698e279b6c1SSam Ravnborgconfig ISA_DMA_API 26991c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 27001c00f016SDavid Rientjes default y 27011c00f016SDavid Rientjes help 27021c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 27031c00f016SDavid Rientjes If unsure, say Y. 2704e279b6c1SSam Ravnborg 270551e68d05SLinus Torvaldsif X86_32 270651e68d05SLinus Torvalds 2707e279b6c1SSam Ravnborgconfig ISA 2708e279b6c1SSam Ravnborg bool "ISA support" 2709a7f7f624SMasahiro Yamada help 2710e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2711e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2712e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2713e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2714e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2715e279b6c1SSam Ravnborg 2716e279b6c1SSam Ravnborgconfig SCx200 2717e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2718a7f7f624SMasahiro Yamada help 2719e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2720e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2721e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2722e279b6c1SSam Ravnborg for other scx200_* drivers. 2723e279b6c1SSam Ravnborg 2724e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2725e279b6c1SSam Ravnborg 2726e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2727e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2728592913ecSJohn Stultz depends on SCx200 2729e279b6c1SSam Ravnborg default y 2730a7f7f624SMasahiro Yamada help 2731e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2732e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2733e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2734e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2735e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2736e279b6c1SSam Ravnborg 27373ef0e1f8SAndres Salomonconfig OLPC 27383ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 273954008979SThomas Gleixner depends on !X86_PAE 27403c554946SAndres Salomon select GPIOLIB 2741dc3119e7SThomas Gleixner select OF 274245bb1674SDaniel Drake select OF_PROMTREE 2743b4e51854SGrant Likely select IRQ_DOMAIN 27440c3d931bSLubomir Rintel select OLPC_EC 2745a7f7f624SMasahiro Yamada help 27463ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 27473ef0e1f8SAndres Salomon XO hardware. 27483ef0e1f8SAndres Salomon 2749a3128588SDaniel Drakeconfig OLPC_XO1_PM 2750a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2751fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2752a7f7f624SMasahiro Yamada help 275397c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2754bf1ebf00SDaniel Drake 2755cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2756cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2757cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2758a7f7f624SMasahiro Yamada help 2759cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2760cfee9597SDaniel Drake programmable wakeup source. 2761cfee9597SDaniel Drake 27627feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 27637feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 276492e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2765ed8e47feSRandy Dunlap depends on INPUT=y 2766d8d01a63SDaniel Drake select POWER_SUPPLY 2767a7f7f624SMasahiro Yamada help 27687feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 27697bc74b3dSDaniel Drake - EC-driven system wakeups 27707feda8e9SDaniel Drake - Power button 27717bc74b3dSDaniel Drake - Ebook switch 27722cf2baeaSDaniel Drake - Lid switch 2773e1040ac6SDaniel Drake - AC adapter status updates 2774e1040ac6SDaniel Drake - Battery status updates 27757feda8e9SDaniel Drake 2776a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2777a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2778d8d01a63SDaniel Drake depends on OLPC && ACPI 2779d8d01a63SDaniel Drake select POWER_SUPPLY 2780a7f7f624SMasahiro Yamada help 2781a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2782a0f30f59SDaniel Drake - EC-driven system wakeups 2783a0f30f59SDaniel Drake - AC adapter status updates 2784a0f30f59SDaniel Drake - Battery status updates 2785e279b6c1SSam Ravnborg 2786d4f3e350SEd Wildgooseconfig ALIX 2787d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2788d4f3e350SEd Wildgoose select GPIOLIB 2789a7f7f624SMasahiro Yamada help 2790d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2791d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2792d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2793d4f3e350SEd Wildgoose get added here. 2794d4f3e350SEd Wildgoose 2795d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2796d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2797d4f3e350SEd Wildgoose 2798d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2799d4f3e350SEd Wildgoose 2800da4e3302SPhilip Prindevilleconfig NET5501 2801da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2802da4e3302SPhilip Prindeville select GPIOLIB 2803a7f7f624SMasahiro Yamada help 2804da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2805da4e3302SPhilip Prindeville 28063197059aSPhilip A. Prindevilleconfig GEOS 28073197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 28083197059aSPhilip A. Prindeville select GPIOLIB 28093197059aSPhilip A. Prindeville depends on DMI 2810a7f7f624SMasahiro Yamada help 28113197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 28123197059aSPhilip A. Prindeville 28137d029125SVivien Didelotconfig TS5500 28147d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 28157d029125SVivien Didelot depends on MELAN 28167d029125SVivien Didelot select CHECK_SIGNATURE 28177d029125SVivien Didelot select NEW_LEDS 28187d029125SVivien Didelot select LEDS_CLASS 2819a7f7f624SMasahiro Yamada help 28207d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 28217d029125SVivien Didelot 2822e279b6c1SSam Ravnborgendif # X86_32 2823e279b6c1SSam Ravnborg 282423ac4ae8SAndreas Herrmannconfig AMD_NB 2825e279b6c1SSam Ravnborg def_bool y 28260e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2827e279b6c1SSam Ravnborg 2828e279b6c1SSam Ravnborgendmenu 2829e279b6c1SSam Ravnborg 28301572497cSChristoph Hellwigmenu "Binary Emulations" 2831e279b6c1SSam Ravnborg 2832e279b6c1SSam Ravnborgconfig IA32_EMULATION 2833e279b6c1SSam Ravnborg bool "IA32 Emulation" 2834e279b6c1SSam Ravnborg depends on X86_64 283539f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2836d1603990SRandy Dunlap select BINFMT_ELF 283739f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2838a7f7f624SMasahiro Yamada help 28395fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 28405fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 28415fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2842e279b6c1SSam Ravnborg 284383a44a4fSMasahiro Yamadaconfig X86_X32_ABI 28446ea30386SKees Cook bool "x32 ABI for 64-bit mode" 28459b54050bSBrian Gerst depends on X86_64 2846aaeed6ecSNathan Chancellor # llvm-objcopy does not convert x86_64 .note.gnu.property or 2847aaeed6ecSNathan Chancellor # compressed debug sections to x86_x32 properly: 2848aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/514 2849aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/1141 2850aaeed6ecSNathan Chancellor depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) 2851a7f7f624SMasahiro Yamada help 28525fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 28535fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 28545fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 28555fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 28565fd92e65SH. J. Lu 2857953fee1dSIngo Molnarconfig COMPAT_32 2858953fee1dSIngo Molnar def_bool y 2859953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 2860953fee1dSIngo Molnar select HAVE_UID16 2861953fee1dSIngo Molnar select OLD_SIGSUSPEND3 2862953fee1dSIngo Molnar 2863e279b6c1SSam Ravnborgconfig COMPAT 28643c2362e6SHarvey Harrison def_bool y 286583a44a4fSMasahiro Yamada depends on IA32_EMULATION || X86_X32_ABI 2866e279b6c1SSam Ravnborg 2867e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 28683120e25eSJan Beulich def_bool y 2869a9251280SLinus Torvalds depends on COMPAT 2870ee009e4aSDavid Howells 2871e279b6c1SSam Ravnborgendmenu 2872e279b6c1SSam Ravnborg 2873e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 2874e5beae16SKeith Packard def_bool y 2875e5beae16SKeith Packard depends on X86_32 2876e5beae16SKeith Packard 2877edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 28785e8ebd84SJason A. Donenfeld 28795e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 2880